Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.

In a bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon. Set this mixture aside.

In a large bowl, cream the softened butter with granulated and brown sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and milk until combined.

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

Scoop tablespoon-sized portions of dough and place them on the prepared baking sheets, leaving space between each cookie.

Bake for 10–12 minutes or until the edges are just golden. Remove from the oven and allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.

To make the icing, whisk together the powdered sugar with 2 tablespoons of milk until smooth and drizzleable.

Once the cookies cool completely, drizzle the icing over the top and sprinkle with purple, green, and yellow sprinkles as desired.