Step 1

Preheat an oven to 350°F (180°C). Line 2 baking sheets with silicone baking mats or parchment paper.

Step 2

In the bowl of an electric mixer fitted with the flat beater, beat together the butter, granulated sugar and brown sugar on medium speed until light and fluffy, about 2 minutes. Stop the mixer and scrape down the sides of the bowl. Reduce the speed to low, add the vanilla and egg and beat until incorporated, about 2 minutes. Add the flour, baking soda, salt and cream of tartar and beat just until the dry ingredients are combined, about 30 seconds. Stop the mixer and scrape down the sides of the bowl. Add the sprinkles and beat until just combined, about 30 seconds more.

Step 3

Using 1 1/2 Tbs. for each cookie (a medium cookie scoop works well), scoop out the dough and roll each ball briefly in your hands to smooth out the rough edges. Place on the prepared baking sheets, spacing the cookies about 2 inches (5 cm) apart.

Step 4

Bake until the tops of the cookies have just begun to crack and the edges are set, about 10 minutes. Transfer the baking sheets to wire racks and let cool for about 5 minutes, then transfer the cookies to the racks and let cool completely. Makes about 30 cookies.

Step 5

Baker’s Note

Step 6

If at any point your dough gets too soft (or if it gets too hard in the fridge), the baking time and final appearance of the cookies may differ. If your cookies don’t spread enough, it could mean that your dough is too cold. If they spread out too thin, try cooling the rest of the dough briefly in the fridge.

Step 7

Recipe by Kate Wood, creator of the blog Wood & Spoon