01 -
Arrange a rack in the middle of the oven and heat the oven to 350°F. Lightly coat a 9x13-inch baking dish with unsalted butter.
02 -
Spread 2 cans of blueberry pie filling evenly across the bottom of the prepared baking dish.
03 -
Sprinkle 1 box of yellow, white, or lemon cake mix evenly over the blueberry pie filling.
04 -
Cut 1 1/2 sticks of cold unsalted butter into thin slices and arrange them evenly over the cake mix, ensuring the entire surface is covered.
05 -
Scatter 2 cups of fresh or frozen blueberries (do not thaw) evenly over the top of the butter layer.
06 -
Bake in the preheated oven for 60-65 minutes, or until the top is golden brown, bubbly, and a crispy crust forms.
07 -
Serve the cake warm, optionally topped with a scoop of vanilla ice cream for added indulgence.