Blueberry Cake with Lemon Frosting

Step 1: Preheat the oven to 180°C/350°F (160°C fan) for 20 minutes before starting the batter. Place one shelf in the middle of the oven and a second beneath it.

Step 2: Grease three 20 cm / 8-inch cake pans with butter and line them with parchment or baking paper.

Step 3: Set aside about one-third of the blueberries for scattering over the cakes later. Toss the remaining blueberries in the flour.

Step 4: Measure out all the batter ingredients and have them ready to add.

Step 5: Whisk the flour, baking powder, and salt in a large bowl. Set aside.

Step 6: Beat the eggs for 30 seconds on speed 6 using a stand mixer fitted with a whisk attachment, or a hand beater.

Step 7: With the beater still running, pour in the sugar over 45 seconds. Beat for 7 minutes on speed 8, or until the mixture is white and tripled in volume.

Step 8: Scatter one-third of the flour mixture over the whipped eggs and beat on speed 1 for 5 seconds. Add half of the remaining flour and mix on speed 1 for 5 seconds. Add the rest of the flour and mix on speed 1 for 5–10 seconds, just until incorporated. Stop as soon as you can no longer see flour.

Step 9: Put the sour cream, hot melted butter, oil, vanilla, and lemon zest into the now-empty flour bowl. Whisk until smooth.

Step 10: Add about 1 1/2 cups of the egg mixture to the sour cream mixture, using about two large scoops. Whisk until smooth.

Step 11: Turn the beater back on at speed 1. Scrape the sour cream mixture into the egg mixture over 15 seconds, then turn off the beater.

Step 12: Scrape down the sides and bottom of the bowl. Beat on speed 1 for 10 seconds. The batter should be thick but soft, not runny or thin.

Step 13: Quickly but gently fold in the flour-coated blueberries.

Step 14: Divide the batter between the prepared cake pans and smooth the surfaces. Scatter the reserved blueberries over the tops.

Step 15: Bake for 25 minutes, or until golden and a toothpick inserted into the center comes out clean. If all the pans do not fit on one shelf, put two pans on the middle shelf and one underneath. Remove the top pans after 25 minutes, move the lower pan to the middle shelf, and bake it for a further 3 minutes.

Step 16: After removing the cakes from the oven, cool them in their pans for 15 minutes. Gently turn them out onto cooling racks upside down. Peel off the baking paper and leave the cakes upside down to cool; this helps flatten any slight dome for neat layers.

Step 17: Frost the layers while they are upside down. Decorate with extra blueberries, lemon slices, and edible flowers, if desired.

Tip: Cool the cake layers completely before frosting so the frosting does not melt.

Step 18: Using the whisk attachment on a stand mixer, beat the butter for 2 minutes until fluffy and creamy and a paler color. Add the cream cheese and beat for 30 seconds, just until smooth.

Step 19: Add the icing sugar or powdered sugar and mix gently on speed 1. If the sugar makes a cloud, cover the bowl with a tea towel. Once most of the sugar is incorporated, beat on high for 2 minutes on speed 7.

Step 20: Add the vanilla and lemon juice, then beat for a further 30 seconds. Use immediately.