Prepare a heat-resistant tray lined with parchment paper.

Cut the lemon in half, squeeze the juice, and divide into 20cc and 10cc portions. Grate the zest of the entire lemon.

In a bowl, whisk the tofu until smooth. Gradually add sugar, vegetable oil, yogurt, 20cc lemon juice, and lemon zest, mixing well after each addition.

Sift rice flour and baking powder into the mixture and combine thoroughly. Pour the batter into the prepared tray and level the surface.

Place a damp cloth in a frying pan, set the tray on top, and add water to reach 1cm height. Cover and steam on low heat for 15–20 minutes. Let cool.

Mix powdered sugar with the remaining 10cc lemon juice to create lemon icing.