Whisk together flour, sugar, baking powder, salt, cinnamon and nutmeg in a medium mixing bowl. In a separate large mixing bowl, whisk eggs, eggnog and melted butter. Gradually stir dry ingredients into wet to form a sticky dough.
Heat waffle griddle to medium-high heat. Grease waffle griddle with cooking spray. Using a small ice cream scoop or cookie scoop, place1 tablespoon scoops of dough in the center of each section of griddle and close lid. Cook for 3-4 minutes. Gently remove cookies with a spatula and place on a wire cooling rack. Repeat with remaining dough.
Once cookies are cooled to room temperature, dust with powdered sugar and serve.
To ensure food safety, eggs should be cooked until both the yolk and the white are firm. Consuming raw or undercooked eggs may increase your risk of foodborne illness, especially for those with certain medical conditions. For recipes that call for eggs that are raw or undercooked when the dish is served, use either pasteurized shell eggs that have been treated to destroy Salmonella, or use pasteurized egg products.