To prepare a cheesy tater tot breakfast casserole recipe, first preheat the oven to 350?F (177?C) and grease two 9-inch (23.25-centimeter) ramekins with nonstick cooking spray. Set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream together the butter and sugar until light and fluffy. Gradually beat in the eggs, beating well after each addition. Add the milk and vanilla and beat until smooth. Pour the batter into the prepared pan and bake for 35 to 40 minutes or until the top is golden brown. Serve warm.