Preheat the oven to 350°F (175°C) and grease the mini bundt pan.
In a mixing bowl, cream the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the vanilla extract.
In another bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, alternating with the milk.
Mix until just combined; do not overmix.
Pour the batter into the greased bundt pan, filling each mold about 2/3 full.
Bake for 20-25 minutes or until a toothpick inserted comes out clean.
Let the cakes cool in the pan for 10 minutes before transferring to a wire rack.
Once cooled, prepare the glaze by mixing powdered sugar with milk until smooth and drizzle over the cakes.