Heat the oven to 350? and prepare two lined cookie sheets or baking pans.
Cream sugar and oil until smooth. Add eggs one at a time, then the vanilla and salt. Mix until evenly combined, scraping bowl to make sure.
Add flour and baking powder, and mix on low just until combined evenly. The dough will be thick and tacky and hold its shape.
Using a spoon or cookie scoop, scoop and then shape dough with the palms of your hands into 1 tbsp. rounds. They won’t spread -- just puff a little -- so you can put a fair number of cookie balls on each sheet. Just leave about an inch of space between each for air flow.
Bake 12 to 14 minutes, until the bottoms are very lightly brown and the tops are dry and form slight cracks. These can go from cakey to dry very easily, so do not overbake.While the cookies are baking, make the glaze and get out your rainbow sprinkles.PRO TIP: The bottoms may not brown if you’re baking on Silpats because of the insulation from the silicone. They’re done, though!
Make the glaze by whisking together in a small bowl the powdered sugar, milk, and vanilla until smooth.
While still warm, dip the tops of the cookies into the glaze and place them on a cooling rack. Sprinkle lightly with rainbow sprinkles while the glaze is still wet. PRO TIP: Put a sheet of wax paper beneath the cooling rack. The glaze will drip down as it sets, and this makes clean up much easier.
Disclaimer: Nutrition information is provided for courtesy purposes only, and is an estimate not verified by medical or nutrition experts. Read the full nutrition disclaimer.