Preheat your oven to 350°F (175°C) and grease and flour a bundt pan.

In a large bowl, combine the flour, baking powder, baking soda, salt, and 1 tablespoon of ground cinnamon.

In another bowl, beat the softened butter and granulated sugar together until light and fluffy.

Mix in the eggs, milk, and vanilla extract until well combined.

Gradually add the dry ingredients to the wet mixture, stirring until just combined.

In a small bowl, combine the brown sugar and remaining 1 tablespoon of cinnamon to make the cinnamon filling.

Pour half of the cake batter into the prepared bundt pan, sprinkle half of the cinnamon filling on top, then add the remaining batter and finish with the remaining cinnamon filling.

Bake for approximately 50 minutes, or until a toothpick inserted comes out clean.

Once done, let the cake cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.

To prepare the icing, mix powdered sugar, milk, and vanilla extract in a small bowl until creamy, then drizzle over the cooled cake.