Line a nine-inch pan with parchment paper, grease the sides, and preheat oven to 345F.
Mix the flour, baking powder, and baking soda in a medium bowl and set aside.
Mix the milk, limoncello, and lemon juice, in a measuring cup and set aside.
Rub the lemon zest into the sugar, then mix in the egg on medium-high speed for about one minute.
With the mixer on medium-high speed, drizzle in the olive oil followed by the wet ingredients,and mix until incorporated.
Reduce speed to low and mix in the dry ingredients.
Pour the cake batter into the prepared pan and bake for 40-50 minutes. Do not open the oven door mid-baking, or the cake willlsink at the center. The cake is done when a toothpick comes out dry from the center of the cake.
Assemble
Place the chilled cake over your serving plate and dollop the mascarpone frosting.
Use the back of a spoon to spread the frosting over the surface of the cake.
Dollop or drizzle the lemon curd over the frosting.
Notes
Ensure all ingredients are at room temperature, and use a kitchen aid to measure the ingredients for best results.
This recipe yields one nine-inch cake or two layers of eight-inch cakes. Divide the frosting between the second cake layer and the top layer.