Averie Cooks

-1 Preheat oven to 350F and line an 8×8-inch pan with aluminum foil, spray with cooking spray; set aside.
Make the Crust:
-1 To a large bowl, add the butter, 1 cup flour, 1/2 cup sugar, and optional salt. Using two forks or a pastry cutter, cut butter into dry ingredients until a sandy mixture with peas-sized buttery bits forms.
-1 Reserve 3/4 cup of this mixture; set aside.
-1 Transfer remaining mixture into prepared pan and using your fingertips or the back of a spatula, lightly press crumbs evenly into pan to form a crust.
-1 Bake for 10 minutes. While crust bakes, make the filling.
Make the Filling:
-1 In a large bowl (same one used to make the crust mixture is fine) add the egg, 1/2 cup sugar, sour cream, vanilla extract, 1/4 cup flour, and whisk until smooth; set aside.
-1 Remove crust from oven and top evenly with pineapple chunks. About 90% of the surface area will be covered with pineapple; chunks will be very close to each other but not quite touching.
-1 Carefully and evenly pour the sour cream mixture over the pineapple, making sure to get it into the corners.
-1 Evenly sprinkle the reserved crust mixture over the top to create the crumble topping.
-1 Bake for about 35 minutes, or until edges and top are set.
-1 Place pan on top of a wire rack and allow bars to cool for at least 1 hour before slicing and serving.