1. Preheat oven to 350F. Line two baking sheets with parchment paper or silicone mats, or grease with butter or cooking spray.
2. In a food processor, grind the oats until it resembles coarse meal, with some large flakes showing but mostly powdery and clumpy.
3. In a large bowl, whisk together all dry ingredients.
4. In a small bowl, whisk together butter, maple syrup, and eggs.
5. Add the wet to the dry ingredients and mix together until combined.
6. Scoop balls of dough about 2 Tbsp. in size onto cookie sheets, about 3 inches apart. (To get a fairly consistent size without a scoop, I scooped out 1/4 cups of dough and split each in half, equaling balls of 2 Tbsp. each.)
7. Bake for 14-16 minutes, rotating and switching the pans halfway through. Cookies are down when the tops have evenly browned. Cool the cookies on wire racks (on the parchment or silicone sheets, if using and if not needed for another batch). Let cookies cool completely before icing.

Icing the cookies

1. In a small bowl, whisk together the sifted powdered sugar and the maple syrup until almost combined, then add the cream and continue whisking until icing is smooth. Add more liquid or sugar as needed for the right consistency, where the icing will flow smoothly but fairly slowly from the end of a spoon. Drizzle over the top of each cookie. The icing should firm after sitting out for about 30 minutes to an hour, though the cookies can certainly be eaten before then.