Preheat the oven: Start by preheating your oven to 350°F (175°C). While it's heating up, grease and flour a 9x13 inch baking pan.
Make the crumble topping: In a large bowl, whisk together the light brown sugar, melted butter, and cinnamon. Stir in the flour until you have a coarse, crumbly mixture. Set it aside.
Prep the cherries: Spread the frozen cherries in an even layer over the bottom of your prepared baking pan. Dollop spoonfuls of sour cream over the cherries, leaving gaps.
Cream the butter and sugar: In a separate large bowl, cream together the softened butter and granulated sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract.
Combine wet and dry ingredients: Gradually add the flour to the wet ingredients, mixing until just combined. Don't overmix!
Pour and top: Pour the batter over the cherries and sour cream in the baking pan, spreading it evenly. Sprinkle the crumble topping generously over the batter.
Bake and cool: Bake the cake for 1 hour and 5 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 20 minutes before serving.
Enjoy your delicious homemade cherry crumble cake!