Ingredients

1 cup (16 Tbsp; 226g) unsalted butter, softened to room temperature

1 and 1/2 cups (300g) granulated sugar

1 egg + 1 egg yolk, at room temperature

2 teaspoons pure vanilla extract

3 cups (375g) all-purpose flour (spooned & leveled)

1 and 1/4 teaspoons baking soda

1/2 teaspoon cream of tartar

1 teaspoon cornstarch

1/2 teaspoon salt

1 cup sprinkles, plus more for decor on top of frosting

3/4 cup (12 Tbsp; 170g) unsalted butter, softened to room temperature (for frosting)

2 and 1/4 cups (270g) confectioners’ sugar

3 Tablespoons (45ml) heavy cream or half-and-half

1 teaspoon pure vanilla extract (for frosting)

1/8 teaspoon salt (for frosting)

Instructions

Step 1: In a large bowl, use a handheld or stand mixer with a paddle attachment to cream the softened butter for about 1 minute on medium speed until smooth. Add sugar and beat until fluffy and light in color. Mix in the egg, egg yolk, and vanilla extract. Scrape down the sides and bottom of the bowl as needed.

Step 2: In a separate medium bowl, whisk together the flour, baking soda, cream of tartar, cornstarch, and salt. With the mixer on low, add the dry ingredients to the wet ingredients slowly in three parts. The dough will be thick and slightly crumbly at first, but continue mixing until it comes together.

Step 3: Gently beat in 1 cup of sprinkles on low speed until evenly mixed. Cover the dough tightly and chill in the refrigerator for at least 3 hours, up to 3 days. Chilling the dough is mandatory for best results.

Step 4: Remove the chilled dough and let it sit at room temperature for 15 to 40 minutes, depending on how long it was chilled, to make it easier to handle but still firm.

Step 5: Preheat your oven to 325°F (163°C) and line two large cookie sheets with parchment paper or silicone mats. Roll the dough into 1.5 tablespoon-sized balls (a medium cookie scoop works well) and place about 8-9 cookies per sheet.

Step 6: Bake for 11-12 minutes, until the edges are slightly browned but the centers are still soft. Let cookies cool on the sheet for 3 minutes, then transfer to a wire rack to cool completely.

Step 7: For the frosting, beat 3/4 cup softened butter in a large bowl until creamy, about 2 minutes. Add confectioners’ sugar, cream, vanilla, and salt with the mixer on low speed. Increase speed to high and beat for 3 full minutes. Adjust by adding more sugar if too thin, more cream if too thick, or a pinch more salt if overly sweet.

Step 8: Frost the cooled cookies as you like and decorate with additional sprinkles on top.

Tips & Variations

Use a medium cookie scoop for uniform cookie size to ensure even baking.

Chilling the dough is essential to prevent spreading and to develop flavor.

Try different colored or themed sprinkles to match holidays or celebrations.

For a dairy-free version, substitute butter with a plant-based alternative and use coconut cream instead of heavy cream.

FAQs

Can I freeze the cookie dough?

Yes, you can freeze the cookie dough before baking. Roll into balls, place on a baking sheet, freeze until firm, then transfer to a freezer-safe bag. Bake from frozen, adding a couple of extra minutes to the baking time.

Why is chilling the dough mandatory?

Chilling solidifies the fats in the dough, which helps prevent spreading during baking and enhances the cookie’s texture. It also allows the flavors to meld and develop fully.