Blend the spinach, vegetable oil, lemon juice, and zest together.

Whip the sugar with the eggs until fluffy, 5-7 minutes, pour in the spinach mixture, and whip again. Turn off the mixer and sift in the flour with the baking powder and vanillin.

Pour the batter into a 16 cm pan and bake for 30 minutes at 170°C, checking with a skewer. It's best to let the sponge cool completely - it won't crumble that way.

For the compote, soak the gelatin in water. Cut some of the strawberries into pieces, blend the rest into puree, and blend the lemon into puree too.

Combine everything except the gelatin in a saucepan and bring to 100°C - it should boil for 3-4 minutes. Remove from heat, add the gelatin, stir, and cool to 50°C.

Pour the compote into a 16 cm ring with the base wrapped in plastic wrap, and freeze for 2-3 hours.

For the mousse, soak the gelatin in ice water. Whisk the mascarpone, powdered sugar, and lemon juice together, and separately whip the cream to stiff peaks.

Melt the gelatin and stir it into the mascarpone mixture, then gently fold in the whipped cream until smooth.

Assemble the cake in an 18 cm ring lined with acetate strip: sponge, 1/3 of the mousse, compote, the rest of the mousse, sponge again, then the remaining mousse. Chill the cake in the fridge for 2-3 hours, or preferably overnight.

Remove the ring and acetate strip - the cross-section reveals bright layers. Decorate the sides with crumbs from sponge trimmings.