Preheat the oven to 175°c. Line two baking trays with parchment.

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

Add the egg and vanilla and mix well for about 1 minute.

In a separate small bowl, use a whisk to combine the dry ingredients: flour, baking soda, baking powder and salt.

Add the dry ingredients to the butter/sugar mixture and slowly stir using a spatula or spoon to work the dry ingredients in. Stop mixing as soon as the flour is combined and large crumbles form. The dough should not be dry.

Set up your work station. Place the sprinkles in a bowl and the 2 tablespoons of milk in a smaller bowl or on a plate.

Using an ice cream scoop, scoop the dough out and tightly press into a ball, ensuring the dough has no breaks and is smooth all around.

Dip the tips of your fingers in milk and coat the ball of dough until it is ever so slightly moistened and sticky.

Roll the ball into the sprinkles and be sure all the dough is coated. Place on a baking sheet with enough room so the cookies can spread (about 6 cookies per tray).

Bake for about 15 minutes or until the cookies have large cracks, puff up and slightly golden brown on the edges.

Allow the cookies to fully cool on the tray.