Preheat oven to 350°.
To prepare cookies, lightly spoon flour into dry measuring cups; level with a knife. Combine flour, quick-cooking oats, baking powder, cinnamon, baking soda, salt, and ground nutmeg in a bowl. Combine brown sugar, granulated sugar, and butter in a large bowl; beat with a mixer at medium speed until well blended. Add vanilla and eggs; beat well. Gradually add flour mixture and cranberries; beat at low speed until combined. Shape dough into 55 (1-inch) balls. Place the balls 2 inches apart on baking sheets coated with cooking spray. Bake at 350° for 15 minutes or until almost firm. Let stand on the baking sheets 2 minutes. Remove cookies from baking sheets; cool completely on a wire rack.
To prepare glaze, combine powdered sugar and remaining ingredients in a bowl, stirring with a whisk. Spoon mixture into a small zip-top plastic bag. Snip a small hole in 1 corner of bag; drizzle glaze over cooled cookies.