It's an easy recipe, but you may not be familiar with using a mixer or the oven. Spray a 13x9x2-inch baking pan with vegetable cooking spray. Put marshmallows evenly in the bottom of the pan. Prepare cake mix according to package directions. Pour batter over marshmallows.
Spoon cherry filling evenly over cake batter.
Bake in a preheated 350-degree oven 45 to 50 minutes. The top of the cake will be bubbly and the marshmallows will be sticky on top of the cake. Carefully open oven and remove pan from oven with hot pads and set on hot pads to cool. Don't forget to turn off the oven. After the cake is cool, cut into squares.