Birthday Cake Sandwich Cookies Recipe

<ul class="ingredients-main-list"><li class="ingredients-single-item">For the cookies:</li><li class="ingredients-single-item">200g all-purpose flour</li><li class="ingredients-single-item">1/2 tsp baking powder</li><li class="ingredients-single-item">1/4 tsp salt</li><li class="ingredients-single-item">115g unsalted butter, softened</li><li class="ingredients-single-item">150g granulated sugar</li><li class="ingredients-single-item">1 large egg, room temperature</li><li class="ingredients-single-item">2 tsp vanilla extract</li><li class="ingredients-single-item">1/2 tsp almond extract (optional)</li><li class="ingredients-single-item">40g rainbow sprinkles (jimmies, not nonpareils)</li><li class="ingredients-single-item">For the filling:</li><li class="ingredients-single-item">115g unsalted butter, softened</li><li class="ingredients-single-item">200g powdered sugar, sifted</li><li class="ingredients-single-item">1 tsp vanilla extract</li><li class="ingredients-single-item">1 tbsp heavy cream</li><li class="ingredients-single-item">Pinch of salt</li><li class="ingredients-single-item">30g rainbow sprinkles, plus extra for decorating</li></ul>

<ul class="equipment-main-list"><li class="equipment-single-item">Stand mixer or hand mixer</li><li class="equipment-single-item">Baking sheets</li><li class="equipment-single-item">Parchment paper</li><li class="equipment-single-item">5cm (2-inch) round cookie cutter</li><li class="equipment-single-item">Wire cooling rack</li></ul>

<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Preheat your oven to 180°C (350°F) and line two baking sheets with parchment paper. In a medium bowl, whisk together the flour, baking powder, and salt until well combined. This even distribution of leavening agents will ensure your cookies rise uniformly.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), cream the butter and sugar together on medium-high speed for about 3 minutes until light and fluffy. This extended beating incorporates air into the mixture, creating a tender cookie texture.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>Add the egg, vanilla extract, and almond extract (if using) to the butter mixture. Beat on medium speed until fully incorporated, scraping down the sides of the bowl as needed. The mixture should look smooth and glossy.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>With the mixer on low speed, gradually add the flour mixture, mixing just until combined. Over-mixing at this stage can develop too much gluten, making your cookies tough rather than tender.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>Gently fold in the rainbow sprinkles by hand using a spatula. Be careful not to stir too vigorously or the sprinkles may bleed their color into the dough. You want distinct, colorful pieces throughout.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Roll the dough out between two sheets of parchment paper to about 6mm (1/4 inch) thickness. Chill the rolled dough in the refrigerator for 15 minutes. This chilling step is crucial as it solidifies the butter, preventing the cookies from spreading too much during baking.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Once chilled, use a 5cm (2-inch) round cookie cutter to cut circles from the dough. Gather scraps, re-roll, and cut again until all dough is used. Place the cookie rounds about 2.5cm (1 inch) apart on the prepared baking sheets.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Bake for 8-10 minutes, until the edges are just barely golden. The centers should still look slightly soft but not wet. Don't overbake – they'll firm up as they cool and we want them to stay soft for the sandwich cookies.</li><li class="MethodStepper"><h4 class="step-title">Step 9</h4>Let the cookies cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely. The cookies must be completely cool before filling to prevent the buttercream from melting.</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>For the filling, beat the softened butter in a clean bowl of your stand mixer (or with a hand mixer) until creamy. Gradually add the sifted powdered sugar, vanilla extract, heavy cream, and salt. Beat on medium-high speed for 3-4 minutes until light and fluffy. The extended beating time creates a silky texture that's easy to pipe.</li><li class="MethodStepper"><h4 class="step-title">Step 11</h4>Gently fold in the rainbow sprinkles, being careful not to overmix to maintain the sprinkle integrity.</li><li class="MethodStepper"><h4 class="step-title">Step 12</h4>Transfer the buttercream to a piping bag fitted with a round tip, or use a spoon to apply. Pipe or spread a generous tablespoon of filling onto the flat side of half the cookies. Top with the remaining cookies, pressing gently to create sandwiches.</li><li class="MethodStepper"><h4 class="step-title">Step 13</h4>For an extra festive touch, roll the exposed edges of the filling in additional rainbow sprinkles. This creates a beautiful visual effect and adds more celebratory flair.</li><li class="MethodStepper"><h4 class="step-title">Step 14</h4>Allow the cookies to set for about 30 minutes before serving. This gives the filling time to firm up slightly, making the cookies easier to handle. Store in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to a week (bring to room temperature before serving for best texture and flavor).</li></ol>