I realize these are summer fruits, and both the higher cost and lesser availability of these fruits might be a disincentive for some of you. Frozen berries are a great option here. Fresh blueberries were oddly enough the most expensive of the three berries, so I bought frozen blueberries and fresh raspberries and blackberries.
Preheat oven to 375 degrees F.
Mix topping ingredients together, stirring in the melted butter last, and set aside.
Roll out dough and shape into 9″ pie pan and set aside.
¼ cup sugar
2 Tbsp water
2 Tbsp cornstarch
1 Tbsp lemon juice
1 tsp vanilla
dash of salt
Cook all the filling ingredients EXCEPT the berries on medium heat, whisking frequently, until it is well blended and thick.
Remove filling from heat and stir in berries.
Spoon filling into pie crust.
Crumble topping over filling, completely covering the berries.
Place pie on a cookie sheet (helps cook the bottom) and bake in oven for 45 minutes.
Cool and serve!
Read more from ragamuffinrecipes.