Preheat oven to 350F degrees. Line a 13 x 9 inch baking pan with aluminum foil and GENEROUSLY spray with non-stick cooking spray. Set aside.
MAKE CRUST:
In a food processor, pulse flour, powdered sugar, and diced butter until crumbly.*
Press dough crust into prepared baking pan. Bake for 20 minutes. Let cool for at least 10 minutes.
MAKE CRUMBLE:
Using an electric hand or stand mixer, combine flour, sugar, and salt. Mix until combined. Add butter and mix until mixture appears crumbly. Set aside.
MAKE PEACH FILLING:
In a large bowl, whisk together eggs and sugar.
Add in the sour cream, flour, and salt.
Fold in sliced peaches.
Pour peach filling over baked crust. Sprinkle crumble topping over top of peach filling. Bake for 45-50 minutes or until top is lightly browned. Let bars cool for at least 1 hour before cutting into bars.
MAKE VANILLA ICING
In a small bowl, whisk powdered sugar, heavy cream and vanilla extract until icing forms.
Cut bars into squares and top with vanilla cooking icing.
Notes
PEACHES: You can use fresh peaches or frozen sliced peaches. Also, you can use canned peaches (you will need 3 15.25 oz. cans).
STORE: In the fridge for up to 5 days.
CRUST: If you don't have a food processor, you can use a medium-sized bowl instead. Whisk together flour and powdered sugar. Using a fork or your fingers, cut in the butter until the mixture becomes crumbly.