Prepare your 8-inch square baking pan by greasing the sides and bottom or lining it with parchment paper. This ensures easy removal later. Set it aside while you prep the filling.
Preheat your oven to 375 degrees Fahrenheit. A properly preheated oven is crucial for even baking.
In a medium mixing bowl, whisk together 1.5 cups all-purpose flour, ½ cup light brown sugar, ½ teaspoon baking soda, ½ teaspoon baking powder, and ¼ teaspoon salt. Make sure everything is well combined to ensure an even rise.
Add the ½ cup melted unsalted butter to the flour mixture and mix until a dough begins to form. The mixture should be crumbly but hold together when pressed.
Reserve about ¾ cup of this mixture for the topping. Set the reserved mixture aside for later use.
Press the remaining dough evenly into the bottom of the prepared pan. This forms the base of your bars, so make it as even as possible.
In a large mixing bowl, combine ½ cup sour cream, 1 cup strawberry pie filling, ¼ cup granulated sugar, 1 tablespoon all-purpose flour, 1 egg, and ½ teaspoon vanilla extract. Using a stand mixer or hand mixer, beat until all ingredients are well combined and smooth.
Pour this creamy filling over the crust in the prepared pan, spreading it evenly with a spatula.
Spoon the strawberry pie filling over the sour cream mixture. Using the back of a spoon, gently make a few swirls to incorporate some of the filling into the cream layer.
Sprinkle the reserved crumb mixture over the top, covering the filling evenly.
Bake in the preheated oven for 25 to 28 minutes, or until the topping is golden brown and a toothpick inserted in the center comes out clean.
Allow the bars to cool completely in the pan before cutting them into squares. This cooling step is important for clean cuts and helps the layers set.
Refrigerate any leftovers in a covered container for up to 3 days. Enjoy your delicious Strawberry Pie Sour Cream Crumb Bars!
