Flourless Lemon Greek Yogurt Cake.

Kitchen Equipment Needed

8-inch ( $20\text{ cm}$ ) Springform Pan or Cake Pan: Lined with parchment paper for easy removal.
Large & Medium Mixing Bowls: For separating and mixing wet and dry ingredients.
Microplane / Fine Zester: Essential for getting fine lemon zest without the bitter white pith.
Whisk & Silicone Spatula: For gentle folding to maintain air pockets.
Wire Cooling Rack: Allows air to circulate around the cake after baking.

1 cup (approx. 240g) Plain Full-Fat Greek Yogurt (strained; avoid runnier varieties)
3 large Eggs (room temperature, separated)
2 tablespoons Fresh Lemon Zest (from roughly 2 medium lemons)
3 tablespoons Fresh Lemon Juice
1/2 cup (approx. 100g) Granulated Sugar or Allulose (for a low-carb version)
1/3 cup (approx. 40g) Cornstarch or Arrowroot Starch (binds the batter smoothly without gluten)
1 teaspoon Pure Vanilla Extract
1/2 teaspoon Baking Powder
1/4 teaspoon Fine Sea Salt

Baking a flourless, yogurt-based cake requires gentle, consistent heat to ensure the eggs set without curdling or cracking the top.

Stage	Heat Intensity / Temp	Purpose
Stage 1: Preheating	$175^\circ\text{C}$ ( $350^\circ\text{F}$ ) / Moderate Oven	Ensures an even initial temperature throughout the oven chamber.
Stage 2: Gentle Bake	$175^\circ\text{C}$ ( $350^\circ\text{F}$ ) / Center Rack	Sets the custard-like structure gently without over-browning the edges.
Stage 3: Oven Rest	Turn Off Heat (Oven door propped open)	Prevents the cake from sinking dramatically due to sudden temperature drop.
Stage 4: Chilling	Refrigerator ( $4^\circ\text{C}$ / $40^\circ\text{F}$ )	Firms up the texture for easy slicing and heightens the lemon flavor.

Preheat your oven to $175^\circ\text{C}$ ( $350^\circ\text{F}$ ) with a rack positioned in the center.
Lightly grease an 8-inch springform pan and line the bottom with a circle of parchment paper.
Carefully separate the eggs: place egg yolks in a large mixing bowl and egg whites in a clean, oil-free medium bowl.

Add the granulated sugar to the bowl with egg yolks. Whisk vigorously for 1–2 minutes until the mixture turns pale yellow and slightly thickened.
Add the Greek yogurt, fresh lemon zest, fresh lemon juice, and vanilla extract. Whisk until smooth and completely combined.

Sift the cornstarch (or arrowroot), baking powder, and salt directly into the wet yogurt mixture.
Whisk gently until no lumps remain. The batter will look smooth and relatively thin.

Beat the reserved egg whites with an electric mixer or hand whisk until soft-to-medium peaks form.
Using a silicone spatula, gently fold one-third of the whipped egg whites into the cake batter to lighten it.
Gently fold in the remaining egg whites in two additions using a sweep-and-fold motion until just incorporated. Do not overmix, or you will deflate the incorporated air.

Pour the batter into the prepared pan and smooth the top with a spatula.
Bake at $175^\circ\text{C}$ ( $350^\circ\text{F}$ ) for 45 to 50 minutes. The edges should be set and golden brown, while the center has a subtle, firm jiggle.
Turn off the oven, crack the oven door open about 2–3 inches, and let the cake sit inside for 10 minutes. This gradual cool-down keeps the top smooth.

Remove the cake from the oven and set it on a wire cooling rack. Allow it to cool completely in the pan to room temperature.
Once cooled, run a thin knife around the inside edge of the pan and release the springform sides.
For best texture: Chill the cake in the refrigerator for at least 2 hours before serving.
Prepare the glaze: Whisk the powdered sugar and 1 tablespoon of lemon juice together until smooth. Add more juice a drop at a time until a drizzle consistency is reached. Pour over the top of the cake and finish with fresh lemon zest.

Refrigerator: Store leftovers covered in an airtight container in the fridge for up to 4 to 5 days. The flavor often improves on day two as the lemon permeates the crumb!
Freezer: Slice the un-glazed cake, wrap individual pieces tightly in parchment and foil, and freeze for up to 2 months. Thaw overnight in the refrigerator before serving.

(Estimated values per 1 Slice / Based on 8 servings with glaze)