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This Rhubarb Slab Pie has a sweet and tart rhubarb and pear filling and a perfectly flaky all-butter crust. It’s a great way to use up fresh rhubarb this spring and this whole recipe comes together pretty easily once you have the crust already made. Serve as dessert with Smash Burgers and this Sweet Tea!
Pies are my love language. This Mixed Berry Pie, Key Lime Pie and this Rhubarb Strawberry Pie are all filled with fresh ripe fruit and taste like summer in every bite!
Ingredients You’ll Need for Rhubarb Slab Pie
- Rhubarb – Vibrant spring vegetable known for it’s pretty pink color and tart and sour flavor! It’s so delicious in this pie paired with ripe pears!
- Pear – Rhubarb can be pretty tart so a couple of pears give the filling a nice balance of tart and sweetness!
- Corn starch – 2 tablespoons will thicken the filling nicely. Substitute with 4 tablespoons of flour if you don’t have cornstarch.
- Egg wash – This is made by whisking an egg with milk. Brush the pie just before baking with this egg wash so your crust will brown better and have a glossy shine!
For the rest of the ingredients, please refer to the recipe index card below!
How To Make Rhubarb Slab Pie
- For the crust. In a large mixing bowl mix together flour, sugar and salt. Grate very cold butter using a box grater then work the butter into the dry ingredients using your hands. You want the butter to be the size of peas. Mix in cold water 1 tablespoon at a time until the dough comes together. Gently knead the dough a couple of times to create layers. Divide the dough into 2 sections, form them into discs then wrap and chill the dough in the fridge for 1 hour or ideally overnight.
- For the filling. In a medium bowl add chopped rhubarb, pear, brown sugar, corn starch, lemon zest, vanilla extract and salt. Mix together then allow to the sit for 10 – 15 minutes.
- Roll out the pie crust. Flour your counter then roll out one of the discs of dough to fit a quarter baking sheet leaving 1-inch overhang. Pour in rhubarb pear pie filling into the crust then transfer to the freezer.
- For the top crust. You can decide the make braids out of the dough, a lattice design or simply roll out the dough to cover the filling. Freeze the whole pie for 30 minutes then brush the top with an egg wash and a sprinkle of turbinado sugar.
- Bake. In a preheated oven, bake your rhubarb pie until the crust is golden brown and the filling is bubbling.
- Serve. Allow the pie to cool for at least 3 hours then serve with ice cream or whipped cream.
Tips and Tricks
- The freezer is your friend. If the dough is ever feeling too soft while you are working with it, pop it back in the freezer for 30 minutes so it can firm back up. Also make sure to freeze the whole pie for 30 minutes before baking to eliminate the possibility of shrinkage in the oven.
- Allow the pie to cool before serving. It’s best to wait at least 3 hours before trying to slice the pie otherwise the filling will spill out and make the bottom crust soggy.
- Make this pie ahead of time. I love to make the pie crust the day before because it’s not only quicker to assemble day of but the extra time allows the gluten in the flour to relax = flakier crust without shrinkage.
Recipe FAQs
How do you keep rhubarb pie from getting soggy?
By using enough cornstarch in the filling and allowing it to cool before slicing. Cornstarch is a very important ingredient used to thickening up the fruit juices so you don’t end up with a runny filling. Also make sure you wait at least 3 hours or until the pie has cooled down before trying to slice it, otherwise the hot filling will rush out and leave you with a soggy rhubarb pie.
How big should you cut rhubarb for pie?
The rhubarb will soften a lot while it cools but because it’s so tart it’s best to cut it into smaller pieces. I find that 1/4 inch pieces is perfect for pie!
Do I need to peel rhubarb before baking?
No, not at all. Just give it a quick rinse and make sure to cut off the ends and your good to go!
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Rhubarb Slab Pie
This Rhubarb Slab Pie has a sweet and tart rhubarb and pear filling and a perfectly flaky all-butter crust. Itโs a great way to use up fresh rhubarb this spring and this whole recipe comes together pretty easily once you have the crust already made. Serve as dessert withย Smash Burgersย and thisย Sweet Tea!
Equipment
- 1 box grater
- 1 Medium-mixing bowl
- 1 Rolling Pin
- 1 9×13 inch Quarter baking sheet
Ingredients
Pie Crust:
- 4 cups 500g all-purpose flour
- 2 tablespoons 30g white granulated sugar
- 2 teaspoons fine-grain sea salt
- 1 1/2 cup 339g unsalted butter
- 1 cup very cold water, divided
Filling:
- 1 pound rhubarb, cut into 1/4-inch pieces
- 2 pears, cored and cut into 1/4-inch slices
- 2/3 cup light brown sugar
- 2 tablespoons corn starch
- Zest from 1 lemon or Meyer lemon
- 2 teaspoons vanilla extract
- Pinch of salt
Toppings:
- 1 large egg + 2 tablespoons milk, whisked together in a small bowl for egg wash
- 1 tablespoon turbinado sugar or demarrara
- Ice cream or whipped cream, for serving
Instructions
For the Pie Crust
- In a large bowl, mix together the flour, sugar and salt. Using a box grater, grate the cold butter atop the flour mixture. Working quickly, and using your hands, break the butter bits into the flour until theyโre evenly distributed and resemble the size of small peas.
- Add 3/4 cup of water and mix. The mixture will be shaggy at this point. From here, add 1 tablespoon of water at a time until the dough comes together (I usually need to add 3 to 4 tablespoons). Flour your counter and dump the dough onto it. Knead a few times more until it comes together. Divide the dough by setting aside 1/3 of the dough (eye ball this measurement; this will act as the bottom of the pie, you want more for the top). Forming two discs, one smaller than the other. Wrap the discs in plastic wrap and transfer to the refrigerator to chill for at least 1 hour, ideally overnight.
- Remove the first disc of dough from the refrigerator and allow to come to room temperature for 10 minutes. Liberally flour your work surface and rolling pin. Begin to roll the dough, being sure to rotate it every so often to avoid sticking, to a 13x10inch rectangle. Use your quarter baking sheet as a guide. Wrap the dough around the rolling pin and unroll it over the baking sheet. Gently fit the dough into the bottom and up the sides. Trim the dough around the pie tin, leaving a 1-inch overhang. Add your filling and transfer the pie to freezer while you roll out the second disc of dough.
- Remove the second disc of dough from the refrigerator and repeat the rolling process as you did with the first disc. You have a couple of options, I chose to do an intricate thick lattice meets braided situation. For this, I rolled about a quarter of the dough into 7ร9 inch rectangle. I sliced that into thick strips and placed them atop the pie. I transferred it to the fridge while I worked on the braids.
To Make the Braids
- I rolled the dough into a big rectangle and sliced thin strips with a sharp knife. I took three of the strips and braided away. I continued this process until I was stressed and got through the dough. I then latticed the big strips with the thin braids. My biggest advice is that the freezer is your friend. If the dough ever gets too soft, transfer it to the fridge on a cutting board. Tuck the edges under or over and then crimp the edge all the way around the slab pie. Put it in the freezer to chill for 30 minutes. This will eliminate the possibility of shrinkage. Preheat the oven (see below for more instructions) and brush the entire thing with egg wash and sprinkle with turbinado sugar.
For the Rhubarb Pie
- In a medium bowl, mix together the rhubarb, pear, brown sugar, corn starch, lemon zest, vanilla extract and salt. Allow to stand, about 10 to 15 minutes, while you assemble the pie crust.
- Pour the filling into the slab pie crust (see above for assembling instructions). Roll the second half of dough and make any sort of design that you like. I chose a few wide strips of pie dough, weaved with a few strands of braided pie dough. Get as fancy as simple as you like. Tuck the edges under and crimp around the entire slab pie. Transfer to the freezer to chill for 30 minutes. Meanwhile, preheat the oven to 400 degrees F. Brush the top of the pie with a generous amoutn of egg wash and sprinkle with about a teaspoon of turbinado sugar.
Bake the pie
- Place the slab pie on a half baking sheet and transfer to the oven to bake for about 20 minutes, until the crust is lightly golden brown. Turn the oven’s heat down to 350 degrees F and bake for an additional 20 to 30 minutes, until the crust is golden brown and the filling is bubbling. Transfer to a cooling rack and allow to cool to room temperature, about 3 hours. If you cut into it before cooling it down, the filling will spill out, but is that the worst thing in the world? Nah. Serve with ice cream or whipped cream.
Notes
Tips and Tricks
- The freezer is your friend.ย If the dough is ever feeling too soft while you are working with it, pop it back in the freezer for 30 minutes so it can firm back up. Also make sure to freeze the whole pie for 30 minutes before baking to eliminate the possibility of shrinkage in the oven.
- Allow the pie to cool before serving.ย Itโs best to wait at least 3 hours before trying to slice the pie otherwise the filling will spill out and make the bottom crust soggy.
- Make this pie ahead of time.ย I love to make the pie crust the day before because itโs not only quicker to assemble day of but the extra time allows the gluten in the flour to relax = flakier crust without shrinkage.
- Pie Crust 101 Guide.ย If you need any help with making this pie crust check out myย Homemade Pie Crust Guide, it goes over everything you need know!
Nutrition
Serving: 12g | Calories: 676kcal | Carbohydrates: 82g | Protein: 8g | Fat: 36g | Saturated Fat: 22g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 1g | Cholesterol: 112mg | Sodium: 605mg | Potassium: 326mg | Fiber: 4g | Sugar: 28g | Vitamin A: 1162IU | Vitamin C: 6mg | Calcium: 92mg | Iron: 3mg
Nutrition information is automatically calculated, so should only be used as an approximation.
Like this Recipe? Please Rate & comment below!
I’m going to try this but, it would be more helpful if authors would use cups instead of lbs. I know its sounds petty but, it really is helpful.