Skip the drive-through and make this Starbucks copycat lemon loaf recipe instead! I spent years perfecting my recipe for an authentic texture (super plush, moist crumb) and bright, real lemon flavor. Recipe includes a how-to video!
Preheat oven to 350F (175C) and lightly grease and flour a 9x5” (23x12cm) bread pan or line with a parchment paper sling. Set aside.
Cream butter, sugar, and zest: In a large mixing bowl, combine sugar, butter, and lemon zest and use an electric mixer to beat until light, fluffy, and well-creamed (about 3-4 minutes on medium-high speed).
In a separate bowl or large measuring cup, whisk together sour cream, egg yolks, lemon juice, and vanilla extract until well-combined, and then stir into the butter mixture on low-speed until fully incorporated. Set aside.
Whisk together the dry ingredients: In a separate mixing bowl, whisk together cake flour, baking powder, and salt. Gently fold the dry ingredients into the wet until completely combined.
Alternate adding wet and dry ingredients. With mixer on low-speed, alternate adding the flour mixture and sour cream mixture to the batter, starting and ending with the flour mixture (I add the flour in 3 parts and the sour cream mixture in 2).
Whip the egg whites. In a separate, medium-sized clean, dry, grease-free mixing bowl, use an electric mixer (with clean, dry beaters), to beat the egg whites on low-speed, then gradually increase to high and beat until you have stiff peaks (mixture will be thick, white, fluffy, and voluminous and the peaks that form when you lift the beaters out should hold their shape and not dissolve back into the bowl).
Fold in egg whites. Add the egg whites to the batter and use a spatula to gently fold together until batter is just combined, smooth and uniform. Pour evenly into prepared loaf pan.
Bake. Transfer pan to center rack of 350F (175C) preheated oven and bake for 74 minutes or until a wooden skewer inserted in the center comes out clean or with a few moist crumbs (no wet batter).
Allow the loaf to cool in the baking pan for 15 minutes before running a knife around the edges to loosen and carefully removing to a cooling rack. Prepare the lemon glaze.
Lemon glaze: Whisk together powdered sugar, 1 Tablespoon lemon juice, butter, and vanilla extract. Continue to add lemon juice as needed until mixture is smooth. Spread or pour evenly over loaf (it’s OK if it’s still warm).
1 ½ cups(190g) powdered sugar, 1-3 Tablespoon lemon juice, 1 ½ Tablespoons salted butter, ¼ teaspoon vanilla extract
Allow loaf to cool and glaze to set for at least 30 minutes after frosting before slicing and serving.
Video
Notes
Substituting all-purpose flour
Cake flour is best for this recipe, but if needed you can substitute 2 cups (250g, yes the weight is the same but the volume is different) of all-purpose flour. If making this substitution, I recommend making a simple syrup to maintain the loaf’s soft, plush texture, otherwise it could be slightly dry (this simple syrup can also be used on the original loaf with cake flour, I just don’t find it necessary there).Simple syrup:After removing the loaf from the oven, combine ¼ cup (60ml) water and ¼ cup (50g) granulated sugar in a small saucepan. Stir over medium heat until sugar is dissolved. Remove from heat and stir in 3 Tablespoons lemon juice. Allow loaf to cool in the pan for 10 minutes, then use a toothpick to poke holes about ½” (1.5cm) apart all over the loaf (the toothpick will not reach the bottom, this is fine). Use a pastry brush to slowly brush 2-3 Tablespoons of simple syrup evenly over the loaf (you will NOT use all of it). Allow the loaf to sit in the pan another 5 minutes then carefully remove to a cooling rack, then prepare the lemon glaze.
Storing
Wrap in plastic or place in an airtight container and store at room temperature for up to 3 days.Note: the loaf may look a little dark when you take it out of the pan or even speckled, this is normal and not concerning.