Preheat your oven to 350°F (175°C) and grease a 9x9 inch baking pan.

Cream together 1/2 cup of softened butter with 3/4 cup of white sugar until light and fluffy.

Add 2 teaspoons of vanilla extract and 2 eggs to the mixture and beat until fully incorporated.

In a separate bowl, whisk together 2 cups of flour, 2 teaspoons of baking powder, and a pinch of salt. Gradually add this to the wet mixture along with 3/4 cup of milk.

Pour half of the batter into the prepared pan and smooth it out evenly.

Mix together 5 tablespoons of cold butter, 1/2 cup of brown sugar, 1 tablespoon of cinnamon, and a bit of flour for the cinnamon swirl. Sprinkle over the first layer of batter and swirl it in.

Dollop the remaining batter over the cinnamon swirl and smooth it out.

For the crumb topping, mix together 1 cup of flour, 1/4 cup of brown sugar, 1/2 teaspoon of cinnamon, and 5 tablespoons of cold butter until crumbly. Sprinkle this over the batter.

Bake for 40-45 minutes until the top is golden and a toothpick inserted comes out clean.

Cool in the pan for 10-15 minutes, then transfer to a wire rack to cool completely before slicing.