Funfetti Sheet Cake Recipe

<ul class="ingredients-main-list"><li class="ingredients-single-item">340g unsalted butter, softened</li><li class="ingredients-single-item">400g granulated sugar</li><li class="ingredients-single-item">4 large eggs, room temperature</li><li class="ingredients-single-item">15ml vanilla extract</li><li class="ingredients-single-item">360g cake flour (or all-purpose flour)</li><li class="ingredients-single-item">3g baking powder</li><li class="ingredients-single-item">1g baking soda</li><li class="ingredients-single-item">5g salt</li><li class="ingredients-single-item">240ml buttermilk, room temperature</li><li class="ingredients-single-item">80g rainbow jimmies/sprinkles (not nonpareils)</li><li class="ingredients-single-item">For the Frosting:</li><li class="ingredients-single-item">225g unsalted butter, softened</li><li class="ingredients-single-item">480g powdered sugar, sifted</li><li class="ingredients-single-item">45ml heavy cream</li><li class="ingredients-single-item">10ml vanilla extract</li><li class="ingredients-single-item">Pinch of salt</li><li class="ingredients-single-item">60g rainbow sprinkles, for decoration</li></ul>

<ul class="equipment-main-list"><li class="equipment-single-item">33x23cm (13x9-inch) baking pan</li><li class="equipment-single-item">Electric mixer (stand or handheld)</li><li class="equipment-single-item">Parchment paper</li><li class="equipment-single-item">Offset spatula</li></ul>

<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Preheat your oven to 175°C (350°F) and position a rack in the center. Grease your 33x23cm baking pan thoroughly, then line with parchment paper, leaving some overhang on the sides to help lift the cake out later. This preparation step ensures your cake won't stick and will come out perfectly intact.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>In a medium bowl, whisk together the cake flour, baking powder, baking soda, and salt. Whisking the dry ingredients separately ensures they'll be evenly distributed throughout the batter, preventing pockets of salt or leavening agents that could affect the cake's texture.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>In the bowl of your electric mixer fitted with the paddle attachment, beat the softened butter on medium speed until creamy, about 1 minute. Add the granulated sugar and cream together until light and fluffy, about 4-5 minutes. Don't rush this step - proper creaming incorporates air into the batter, creating a tender crumb structure.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>Add the eggs one at a time, beating well after each addition and scraping down the sides of the bowl as needed. Mix in the vanilla extract. The mixture might look slightly curdled at this point, but don't worry - it will come together when you add the dry ingredients.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>With the mixer on low speed, add the flour mixture in three parts, alternating with the buttermilk, beginning and ending with the flour (flour-buttermilk-flour-buttermilk-flour). Mix just until combined after each addition. This alternating method prevents gluten from developing too much, resulting in a more tender cake.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Gently fold in the rainbow jimmies using a rubber spatula. Be careful not to overmix, as this can cause the sprinkles to bleed their color into the batter. Use traditional cylinder-shaped jimmies rather than nonpareils (the tiny round sprinkles), as jimmies hold their shape and color better during baking.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Pour the batter into your prepared baking pan, using an offset spatula to spread it evenly to the corners. Give the pan a couple of gentle taps on the counter to release any large air bubbles that might have formed.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Bake for 28-32 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs (but no wet batter). The cake should spring back slightly when gently pressed in the center, and the edges will just begin to pull away from the sides of the pan. Be careful not to overbake, as this can result in a dry cake.</li><li class="MethodStepper"><h4 class="step-title">Step 9</h4>Allow the cake to cool in the pan for 15 minutes, then use the parchment paper overhang to carefully lift it out and transfer to a wire rack to cool completely. Patience is key here - frosting a warm cake will cause the buttercream to melt!</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>While the cake cools, prepare the frosting. In a large bowl using an electric mixer, beat the softened butter on medium speed until completely smooth and creamy, about 2 minutes. Gradually add the sifted powdered sugar, heavy cream, vanilla extract, and salt, beating on low speed until combined, then increasing to high speed and beating for 3 full minutes. The extended beating time incorporates air into the frosting, making it light and fluffy.</li><li class="MethodStepper"><h4 class="step-title">Step 11</h4>Once the cake is completely cool, spread the frosting over the top in swooping, decorative swirls using an offset spatula. The swoops and swirls will create little valleys that catch and display the sprinkles beautifully. Immediately top with additional rainbow sprinkles before the frosting sets.</li><li class="MethodStepper"><h4 class="step-title">Step 12</h4>For the cleanest slices, chill the frosted cake for 30 minutes before cutting. Store leftovers in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to 5 days. Let refrigerated cake come to room temperature before serving for the best flavor and texture.</li></ol>