Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish. In a medium bowl, mix together the yellow cake mix (reserving 1 cup for the crumble), egg, and melted butter until combined. Press the mixture into the bottom of the prepared baking dish to create an even layer.
Step 2: Make the Pumpkin Filling
In another bowl, whisk together the pumpkin purée, eggs, granulated sugar, brown sugar, milk, vanilla extract, cinnamon, nutmeg, cloves, and salt until smooth. Pour the pumpkin mixture over the cake base and spread it out evenly.
Step 3: Create the Crumble Topping
In a separate bowl, mix the reserved 1 cup of yellow cake mix, brown sugar, and cinnamon. Add the cold, cubed butter and use a pastry cutter or your fingers to work the butter into the dry ingredients until it forms a crumbly texture. Sprinkle the crumble topping evenly over the pumpkin filling.
Step 4: Bake the Cake
Bake the cake in the preheated oven for 40-45 minutes, or until the top is golden brown and the filling is set but still slightly gooey in the center. Allow the cake to cool for at least 15 minutes before slicing.
Notes
Serve warm with a scoop of vanilla ice cream or a drizzle of caramel sauce for extra indulgence.
Store leftovers in the refrigerator for up to 3 days and reheat before serving.