01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well blended.
03 - In a large bowl, beat the softened butter and granulated sugar until light and fluffy, approximately 2-3 minutes.
04 - Add eggs one at a time, beating thoroughly after each addition. Blend in vanilla extract and lemon zest until fully incorporated.
05 - Gradually add the dry ingredients to the wet mixture, alternating with the milk. Mix until a soft, cohesive dough forms, being careful not to overmix.
06 - Scoop tablespoon-sized portions of dough and roll into 4-inch logs. Shape each log into a ring, pinching the ends firmly to seal.
07 - Place the cookie rings on the prepared baking sheets, leaving approximately 2 inches of space between each ring to allow for slight spreading.
08 - Bake for 12-15 minutes or until the bottoms are lightly golden. Remove from oven and let cool completely on a wire rack before icing.
09 - Whisk together powdered sugar, milk, and vanilla extract until smooth and slightly thickened. The icing should coat the back of a spoon without dripping off.
10 - Dip the top of each cooled cookie into the icing, allowing excess to drip off. Immediately sprinkle with colored sprinkles. Let the icing set completely before serving or storing.