Preheat oven to 350°F and line the bottoms of three 6” cake pans with a round of parchment paper. Set aside.
In a large mixing bowl, use an electric mixer to beat eggs on medium speed for 1 minute. Slowly pour in the sugar while mixing. Once all the sugar has been added, beat for at least 10 minutes until the mixture has tripled in volume and become a pale yellow colour.
In a small bowl, stir together the cake flour and baking powder. Using a fine mesh sieve, sift these dry ingredients into the egg mixture ⅓ at a time. Use a silicone spatula to fold the flour in to combine. Don’t overmix otherwise you will deflate too much air from the batter.
Divide the cake batter evenly into your cake pans (I portioned out approximately 200g into each of my 6” cake pans). Bake cakes for 23-25 minutes or until a toothpick inserted in the middle comes out clean.
Let cakes cool in the pans for 10-15 minutes until cool enough to handle. Run a knife or offset spatula around the edges of the cake to release from the pan and turn the cake out upside down onto a cooling rack, peel off the parchment paper, and let cool completely before frosting.
In a small bowl, stir together espresso powder, hot water, and coffee liqueur and set aside for when you’re ready to assemble the cake.