1 cup (227 grams) unsalted butter, softened1 cup (200 grams) granulated sugar1 cup (220 grams) firmly packed light brown sugar1 cup (240 grams) speculaas cookie butter2 large eggs (100 grams), room temperature1 tablespoon (15 grams) whole milk, room temperature2 teaspoons (8 grams) vanilla extract31/2 cups (438 grams) all-purpose flour1 teaspoon (5 grams) baking soda1 teaspoon (5 grams) baking powder White sparkling sugarBlue sparkling sugar48 to 50 unwrapped Hanukkah gelt milk chocolate coins
Preheat oven to 375°F (190°C). Line baking sheets with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, beat butter, granulated sugar, and brown sugar at medium speed until fluffy, 2 to 3 minutes, stopping to scrape sides of bowl. Beat in cookie butter. Add eggs, one at a time, beating well after each addition. Beat in milk and vanilla.
In a medium bowl, whisk together flour, baking soda, and baking powder. With mixer on low speed, gradually add flour mixture to butter mixture, beating just until combined and stopping to scrape sides of bowl.
In a small bowl, place white sparkling sugar. In another small bowl, place blue sparkling sugar.
Using a 11/2 -tablespoon spring-loaded scoop, scoop dough (28 to 30 grams each), and roll into smooth 11/2 -inch balls. Roll in desired sparkling sugar until well coated. Place 2 to 21/2 inches apart on prepared pans.
Bake, one batch at a time, until bottom edges are lightly golden brown, 8 to
minutes, rotating pan halfway through baking. Immediately press 1 unwrapped gelt into center of each cookie. Let cool on pan for 5 minutes. Remove from pan, and let cool completely on wire racks.