Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan.
In a large bowl, whisk together flour, granulated sugar, brown sugar, baking powder, salt, and cinnamon until well combined.
In another bowl, cream the softened butter and sugars until light and fluffy (about 3 minutes).
Add eggs one at a time, mixing well after each addition. Pour in the milk and mix until smooth.
Gradually add dry ingredients to wet mixture, stirring gently until just combined.
Pour half of the batter into the prepared pan. Sprinkle with your favorite topping (like streusel) before adding the remaining batter on top.
Bake for 30-35 minutes or until golden brown and a toothpick comes out clean.
