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

In a medium mixing bowl, whisk together the flour, baking powder, and salt. Add the dry mixture to the wet mixture and beat with an electric mixer until combined.

Cover the bowl with plastic wrap or a clean kitchen towel and refrigerate the dough for 30 minutes.

With clean hands: Roll the chilled dough into 30 1-inch balls and place on cookie sheets lined with parchment paper, leaving at least 1 inch of space between each cookie. (They won’t spread out too much.) Place the cookie sheets in the refrigerator to chill the dough balls for 30-60 minutes before baking.

While the dough balls chill, preheat the oven to 350F.

Bake the cookies for 10 minutes at 350F until set and lightly browned on the bottom. Transfer the cookies to a wire cooling rack to cool completely to room temperature before frosting.

While the cookies cool, make the glaze: Pour the powdered sugar and vanilla extract into a small mixing bowl. Add the cream or milk 1 T at a time, stirring well between each addition, until it reaches the point where it gently drips off the spoon—just thin enough to drizzle, but not so thin that it will run right off the cookies. If too thin, add more powdered sugar a tablespoon at a time. Stir in the orange zest last.