In a large bowl, cream butter and sugar until fluffy. Add in the egg and vanilla extract until fully mixed.

Preheat oven to 400 degrees F. In a medium size bowl, combine the flour, baking powder and salt.

Alternating, add in the flour mixture and milk to the butter. Dough shouldn't be too sticky.

Grease a mini donut pan for baking. taking balls of about 1 1/2 Tbsp, roll the dough in your hands into a rod shape and place in donut pan connecting the ends to make a full circle. Repeat for the entire pan.

Place in oven and bake for 6 minutes. Let stand in pan for a few minutes before removing to cool.

In a small bowl combine the milk, powdered sugar, and vanilla. Add a little more milk if needed to get the desired consistency. Add in green food coloring to achieve a dark green shade.

Dip the top of the cookies in the icing and place on rack that allows the excess to drip through. Decorate with sprinkles before the icing sets.