Using the end of season fruit to create these amazing blackberry peach crumb bars.
Preheat oven to 375° F. Grease a 9x13 inch baking pan with butter.
Combine together the flour, 1 cup of white sugar, baking powder, salt and spices into a food processor. Pulse a few times to make sure it's mixed together.
Add the cubed butter into it and run until the dough mixture looks like wet sand and will stick together if you press it between your fingers. Pulse the egg in until the dough is mixed.
Press half of the mixture into the bottom of the greased pan and reserve the other half for the crumb topping.
In a clean food processor, combine the blackberries, peaches, lemon juice, lemon zest, and vanilla extract. Process together until the mixture looks like a thick soup.
Add sugar and cornstarch to food processor and pulse together until combined. You're looking for the consistency of a thick preserve or thinned out jam.
Pour the blackberry peach mixture onto the bottom crust and ensuring that the mixture is spread evenly over the crust. Crumble the remaining dough mixture on top of the blackberry filling.
Place on a cookie sheet and bake in the oven for 30-40 minutes until the top is golden brown. Let cool completely before cutting. It may help to freeze the bars slightly to cut and remove them without crumbling apart.