Step 1: Preheat Your Oven

Set your oven to 350°F (175°C). Grease the baking dish lightly with butter or non-stick spray.

Step 2: Layer the Berries

Place all the berries in the baking dish. If using frozen berries, no need to thaw. Sprinkle sugar, lemon juice, and vanilla extract over the berries and stir gently to coat.

Step 3: Add the Cake Mix

Evenly pour the dry cake mix directly over the berries. Do not stir. The cake mix acts as a magical topping that will absorb moisture and create a crust.

Step 4: Add Butter

Slice the butter into thin pats and arrange them evenly on top of the cake mix. Make sure most of the surface is covered with butter to prevent dry spots.

Step 5: Bake the Cake

Place the dish in the oven and bake for 45–50 minutes, or until the top is golden brown and bubbling around the edges. Remove and let it cool slightly before serving.