• Preheat the oven to 180℃. Prepare a deep baking sheet (I used 27x34 cm).
• Mix the eggs, egg white, sour cream with lemon drops, and sugars until the mixture gets creamy on high speed in a bowl. It can take 4 minutes. Add oil and vanilla extract. Whisk until well combined – for 4 minutes.
• Add flour, chia seeds and baking powder. Whisk until the flour disappears. Do not over-mix!
• Pour the batter into a baking tray and bake for 25-30 minutes or until the toothpick comes out clean. Take the lemon cake out of the oven and let cool in the baking tray.

Syrup

• Heat juice of 1 lemon in a pan. Add icing sugar and mix well. While the cake is still hot (15 minutes after you took it out of the oven), poke some holes into the cake. Pour the lemon syrup over the cake. I used only half of the liquid. Let cool completely.

Cream

• In another bowl cream the butter with mascarpone cheese with a paddle attachment. Add icing sugar and on low speed for 8 minutes or more.