Instructions: Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9x13-inch baking dish or pan.
Prepare the Cake Batter: In a large mixing bowl, combine the yellow cake mix, water, vegetable oil, and eggs. Beat on medium speed for 2 minutes until well combined and smooth.
Add the Cherry Pie Filling: Spread the cherry pie filling evenly over the layer of cake batter in the baking dish.
Add the Streusel Topping (optional): Sprinkle the streusel topping evenly over the top of the cake batter.
Bake: Place the baking dish in the preheated oven and bake for 40 to 45 minutes, or until the cake is golden brown and a toothpick inserted into the center comes out clean.
Cool and Serve: Serve the cherry pie cake warm or at room temperature, optionally topped with a scoop of vanilla ice cream or whipped cream.