Pulse in a food processor shredded coconut and gel food coloring for 20 sec. Let it dry in the oven for 20 minutes ate 200 F.
Sponge:
Melt the butter, add eggs whisk well with the fork. Add remaining ingredients, mix together and transfer batter in a microwave-proof bowl greased with cooking spray (4.5 inches).
Microwave on high for ~4-6 minutes. Check the sponge, the center should be firm. Cooking time highly depends on the power of the microwave. Let it cool completely. Slice into 3 layers with the sharp knife.
Frosting:
Using hand mixer beat on high soft butter, adding powdered sweetener.
Add cream cheese (room temperature) and beat for ~1 minute, adding vanilla extract and lime zest (optional).
Assemble the cake by layering sponge with frosting.
Decorate with sprinkles.
Refrigerate for 2 hours.
Preheat the oven to 350°F.
Using an electric mixer, beat the eggs with the whisk attachment for 1 min on high. With the mixer on, gradually add erythritol and continue beating on high speed ~5 min.
The mixture will be thick and fluffy. Add soft coconut oil in thirds, and mix slowly.
Slowly fold in shredded coconut.
Pour the batter into the prepared pan. Bake for 20 minutes.
Dissolve gelatine according to instructions.
Mix together mascarpone, cream cheese, erythritol, and vanilla extract matcha powder and mix. Add dissolved room-temperature gelatine.
After the sponge is baked and cooled down, pour over the filling and refrigerate overnight.
Can be stored in a fridge up to 5 days, or frozen up to a month.
