Place oats in a food processor and process few times, until it resembles coarse flour (not fine but not whole oats). Place the oats in a large mixing bowl.
Add flour, baking powder, soda, salt, cinnamon and cloves and whisk it all together.
In another large mixing bowl, using an electric mixer, mix melted butter and both sugars together until smooth.
Add extract and the egg and mix until smooth.
Add the dry ingredients to the wet ingredients and mix just until incorporated.
Cover the bowl with cookie dough with a plastic wrap and chill for at least 2 hours, preferably overnight.
When ready to bake, preheat oven to 350 degrees F.
Line a baking sheet with parchment paper.
Drop rounded tablespoons of dough onto the sheet, leaving plenty of space between them. The dough will spread during baking.
Bake cookies for 14 to 15 minutes, or until golden brown around the edges and set in the center.
Cool for 5 minutes on the baking sheet. Transfer onto a cooling rack to cool completely.
!to make the glaze:
Whisk sugar with milk. Dip each cookie in glaze. Set back on cooling rack.