Blueberry Bottom Cake

Ingredients (9)

• ✓ 1 (15.25 ounce) package white cake mix (such as Pillsbury® Classic White)
• + 1 cup water add to pantry
• + 3 eggs add to pantry
• + ½ cup vegetable oil add to pantry
• + 4 cups fresh blueberries add to pantry
• + 1 cup white sugar add to pantry
• + 1 (3 ounce) package strawberry-flavored gelatin add to pantry
• + 3 cups miniature marshmallows add to pantry
• + 2 cups frozen whipped topping (such as Cool Whip®) add to pantry