In a medium saucepan (don’t turn on the heat yet), add the brown sugar and vanilla bean. Mix the vanilla bean caviar throughout the sugar until it’s evenly dispersed. Add the cubes of butter and place over medium heat. Heat until the butter is melted. Give it a good stir and then turn the heat off. Mix in the brown rice syrup, angostura’s bitters, salt and eggs. Mix until smooth.
Roll out your pie dough and set in the your crust (see above for full instructions). Preheat the oven to 350 degrees F. Add the walnuts to the pie shell. Pour the filling into the pie crust and transfer to the freezer for 15 minutes. Brush the edges of the pie crust with egg wash and transfer to a baking sheet. Place the baking sheet/and pie in the oven to bake for 45 to 50 minutes, until the center has set (it may rise slightly) and the crust is golden brown. Be sure to check on it periodically throughout the baking process—if at any time the crust gets too brown, you can place a piece of foil over it to protect it from browning more.
Now, here’s the deal with this pie: it needs to cool completely to be able to cut it into perfect slices, but I didn’t wait (you’ll see the top picture isn’t perfect) enough and it was AMAZING. So, if you can’t wait, then it’s ok. Serve with whipped cream and/or ice cream.