Preheat the oven to 350 degrees F (175 degrees C) and grease your baking pan.

Make the crumb topping: In a small bowl, whisk together the flour, both sugars, cinnamon, and butter with a fork or pastry cutter until crumbly. Set aside.

Make the cake batter: In a large bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt. Set aside.

In another large bowl, cream together the softened butter and sugar until light and fluffy.

Beat in the eggs one at a time, mixing well after each addition.

Stir in the vanilla extract.

Alternate between adding the dry ingredients and the milk to the wet ingredients, beginning and ending with the dry ingredients. Blend until just combined – don't overmix!

Make the cinnamon swirl: In a separate small bowl, combine the brown sugar and cinnamon.

Spread half of the cake batter into your prepared pan. Sprinkle with half of the cinnamon swirl mixture. Top with the remaining batter and sprinkle with the rest of the cinnamon swirl.

Top the cake with the crumb topping.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean and the topping is golden brown.

Let the cake cool in the pan for 15-20 minutes before serving warm or at room temperature.