Lemony Zucchini Cake with Earl Grey Buttercream

• Preheat the oven to 350 F (175 C). Grease + flour four 6-inch (or two 8-inch) cake pans and set aside.
• Sift together the flour, baking powder, baking soda and salt. Set aside.
• In a large bowl mix the oil, sugar and lemon zest until well combined. Beat the eggs in one at a time.
• Add 1/2 the flour mixture and stir to combine. Add the rest of the flour and stir until just combined.
• Add the zucchini, buttermilk and lemon juice. Mix gently until the zucchini is just mixed in.
• Divide the batter evenly among the prepared cake pans. Bake for 24-26 minutes for 6-inch cakes (or 25-30 minutes for 8-inch cakes).
• Let them cool on a wire rack for 10-15 minutes before removing the cakes from their pans.

To Assemble:

• Use a serrated knife to level each cake layer, removing the domed top so you get nicely even, level layers.
• If you baked 8-inch cakes like me, you'll need to use a serrated knife to split each layer in two (so you end up with 4 thin layers).
• Take one layer of cake and place it onto a serving plate. Brush the layer with some of the lemon syrup (leftover from making the candied lemons) and then top with 1/4 of the buttercream, spreading it out into an even layer. Repeat the layering of cake, lemon syrup, buttercream until you've stacked up all the cake layers and frosted the top.
• Stir together the glaze ingredients until a thick, pourable glaze is achieved. Pour it all over the top of the cake, coaxing it to the edges so that it drips down the sides.
• While the glaze is still wet decorate the cake with the candied lemon slices and pearl sugar.

• Place 3/4 cup of the butter into a saucepan with the loose tea. Heat over medium heat until the butter melts, then reduce the heat to low and simmer for 5 minutes. Remove from the heat and let the tea steep for 5 minutes more. Strain the butter through a fine-mesh sieve set over a bowl and refrigerate it until it reaches the same consistency as softened butter (20-30 minutes). Small bits of tea may remain in the butter.
• Place the egg whites and sugar in the bowl of a stand mixer. Whisk them together by hand to combine. Fill a medium saucepan with a few inches of water and place it over medium-high heat. Place the mixer bowl on top of the saucepan to create a double boiler. The bottom of the bowl should not touch the water. Whisking intermittently, heat the egg mixture until it registers 160 F (70 C) on a candy thermometer or is hot to the touch. Carefully fit the mixer bowl onto the stand mixer.
• With the whisk attachment, beat the egg white mixture on high speed for 8-10 minutes, until it holds medium-stiff peaks. When done, the outside of the mixer bowl should return to room temperature and no residual heat should be escaping from the meringue out of the top of the bowl. Stop the mixer and swap out the whisk attachment for the paddle.
• With the mixer on low speed, add the vanilla and salt. Next add the tea-infused butter and remaining 3/4 cup of butter a couple tablespoons at a time. Once incorporated, turn the mixer onto medium-high and beat until the buttercream is silky smooth (3-5 minutes).

• Slice the lemons as thinly as possible.
• Place the sugar and water into a pot over a medium heat and stir until the sugar dissolves.
• Add the lemon slices to the pot and bring to the boil. Turn down to simmer and leave for 15 minutes.
• Lift the lemon slices out of the syrup with a fork and leave on a wire rack set over a piece of baking paper to dry and cool.
• Keep the resulting lemon syrup in the pot for brushing onto the cakes.