Preheat your oven to 350°F (175°C) and prepare two 8-inch round cake pans by greasing and lining them with parchment paper.

In a large mixing bowl, sift together the all-purpose flour, baking powder, and salt.

In a separate bowl, whisk the eggs and granulated sugar until pale and thick, about 5-7 minutes.

Gently fold in the vanilla extract and lemon zest, followed by the dry ingredients until just combined.

Divide the batter evenly between the prepared pans and bake for 18-20 minutes, until the tops are springy and a toothpick inserted comes out clean.

Allow the cakes to cool completely in the pans.

While the cakes are cooling, prepare the limoncello syrup by combining water, sugar, and limoncello over medium heat, stirring until the sugar dissolves.

Let the syrup cool to room temperature while preparing the mascarpone filling.

In a mixing bowl, add mascarpone cheese, powdered sugar, lemon juice, and vanilla extract, then beat until smooth and creamy.

In a separate bowl, whip heavy cream until soft peaks form and fold into the mascarpone mixture.

Slice each cooled sponge cake layer in half horizontally, creating four layers in total.

Brush the first layer with cooled limoncello syrup, then spread a portion of mascarpone filling on it.

Repeat with remaining layers and chill the assembled cake for at least 1 hour.

To make the glaze, mix powdered sugar with limoncello syrup until smooth and drizzle over the chilled cake.

Garnish with additional powdered sugar, fresh lemon slices, and mint before serving.