Cover the bottom of the 15cm mousse ring with aluminum foil twice. Add melted butter to crushed biscuits, and mix well. Put the biscuit mixture in the mousse ring, and press into the bottom. Let it sit in a fridge.

Preheat your oven to 180℃ / 356 F. Add granulated sugar to smoothed cream cheese, and mix well for 1-2 mins until smooth and glossy. Add whole egg and egg yolk, and gently stir until smooth. Add yogurt, and mix well until well combined.

Add heavy cream, and mix well until well combined. Add vanilla oil and lemon juice, and mix well. Sift flour over the mixture, and stir well until you don't see flour left.

Strain it, and then pour it into the mousse ring. Pour hot water into a baking sheet, and bake it at 160℃ / 320 F for 53 mins. If the water is running low during baking, add more. After baking, leave it in the closed oven for 20-30 mins, then remove. Cool down, and refrigerate overnight.

Slide the knife along the edges of the ring, and remove the cake from the ring. It's done!