Fluffy Castella Sponge Cake – Light, Airy & Perfectly Sweet

Step 1: Preheat Oven
Preheat your oven to 325°F (160°C). Line a loaf pan (about 9×5 inches) with parchment paper, extending up the sides for easy removal.
Step 2: Whip Eggs & Sugar
In a large mixing bowl (stand mixer or hand mixer), combine eggs, sugar, and cream of tartar (if using). Whip on high speed for 8–10 minutes until thick, pale yellow, and tripled in volume. The mixture should fall in a slow ribbon when you lift the whisk.
Step 3: Add Honey
Gently fold in the honey using a spatula until fully incorporated.
Step 4: Sift in Flour
In three additions, gently sift the flour over the egg mixture. Fold carefully after each addition — do not overmix or deflate the batter.
Step 5: Pour Into Pan