Blackberry Lime Sheet Cake Recipe

<ul class="ingredients-main-list"><li class="ingredients-single-item">280g all-purpose flour</li><li class="ingredients-single-item">2 tsp baking powder</li><li class="ingredients-single-item">1/2 tsp salt</li><li class="ingredients-single-item">170g unsalted butter, softened</li><li class="ingredients-single-item">300g granulated sugar</li><li class="ingredients-single-item">3 large eggs, room temperature</li><li class="ingredients-single-item">2 tsp vanilla extract</li><li class="ingredients-single-item">Zest of 2 limes</li><li class="ingredients-single-item">2 tbsp fresh lime juice</li><li class="ingredients-single-item">240ml buttermilk (or 230ml milk + 1 tbsp lemon juice)</li><li class="ingredients-single-item">250g fresh blackberries (plus extra for decoration)</li><li class="ingredients-single-item">1 tbsp flour (for coating berries)</li><li class="ingredients-single-item">For the frosting:</li><li class="ingredients-single-item">225g cream cheese, softened</li><li class="ingredients-single-item">115g unsalted butter, softened</li><li class="ingredients-single-item">350g powdered sugar, sifted</li><li class="ingredients-single-item">Zest of 1 lime</li><li class="ingredients-single-item">1 tbsp fresh lime juice</li><li class="ingredients-single-item">1 tsp vanilla extract</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 hand mixer)</li><li class="equipment-single-item">Microplane or zester</li><li class="equipment-single-item">Parchment paper</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). Line your 33x23cm baking pan with parchment paper, leaving some overhang on the sides to help lift the cake out later. Lightly grease any exposed areas of the pan.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>In a medium bowl, whisk together the flour, baking powder, and salt. This pre-mixing ensures even distribution of the leavening agents throughout your batter, preventing any bitter pockets of baking powder.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>In a large bowl, use your electric mixer to cream the butter and sugar together on medium-high speed for 3-4 minutes until pale and fluffy. This extended beating incorporates air into the mixture, creating a lighter, more tender cake structure.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>Add the eggs one at a time, beating well after each addition until fully incorporated. Don't rush this step - it helps create an emulsion that keeps your cake moist. Mix in the vanilla extract, lime zest, and lime juice until combined.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>Gradually add the flour mixture to the butter mixture in three additions, alternating with the buttermilk (beginning and ending with flour). Mix on low speed just until combined after each addition. Overmixing develops gluten, which can make your cake tough rather than tender.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Toss the blackberries with 1 tablespoon of flour until lightly coated. This flour coating helps suspend the berries in the batter, preventing them from sinking to the bottom during baking. Gently fold the flour-coated blackberries into the batter using a spatula.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Pour the batter into your prepared pan, spreading it evenly with a spatula. Tap the pan gently on the counter a few times to release any large air bubbles that could create holes in your cake.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Bake for 28-32 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs (but no wet batter). The cake should spring back lightly when touched in the center. Be careful not to overbake, as this will dry out your 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 overhang to carefully lift it out onto a wire rack to cool completely. The cake must be completely cool before frosting, otherwise the frosting will melt.</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>For the frosting, beat the cream cheese and butter together until smooth and creamy, about 2 minutes. The temperature of these ingredients is crucial - if too cold, your frosting will be lumpy; if too warm, it will be runny.</li><li class="MethodStepper"><h4 class="step-title">Step 11</h4>Gradually add the sifted powdered sugar, mixing on low speed until incorporated, then increase to medium-high and beat until light and fluffy. Mix in the lime zest, lime juice, and vanilla extract until well combined.</li><li class="MethodStepper"><h4 class="step-title">Step 12</h4>Once the cake is completely cool, spread the frosting evenly over the top using an offset spatula. For a more rustic look, create swoops and swirls in the frosting. Garnish with additional fresh blackberries and lime zest if desired.</li><li class="MethodStepper"><h4 class="step-title">Step 13</h4>For the best flavor, refrigerate the cake for at least 30 minutes to allow the flavors to meld together. Remove from the refrigerator about 20 minutes before serving to take the chill off. The cake will keep, covered in the refrigerator, for up to 4 days.</li></ol>