Preheat oven to 350F

Warm eggs in a bowl of warm water for 5 minutes.

In a stand mixer on high speed, whip eggs for 15 minutes until fluffy, light colored and doubled in volume.

Meanwhile, in a small bowl, sift flour, baking powder and salt.

Meanwhile, in a medium bowl, stir together vanilla, lemon juice, lemon zest and melted butter.

On low speed, mix flour into the whipped eggs.

On low speed, mix butter and lemon juice mixture until homogenous.

Pour batter into baking pan.

Bake for 20 minutes until toothpick comes out clean.

Cool cake on counter.

Warm eggs in small bowl of warm water for 5 minutes and set aside.

In a small bowl on high speed, whip whipping cream into soft peaks. Place whipping cream into refrigerator to keep cool.

In a small pot, dissolve gelatin into lemon juice and set aside.

In a clean, large bowl and clean mixing beaters, break eggs and add granulated sugar.

On high speed, whip eggs with sugar for 5-10 minutes until fluffy, light colored and doubled in volume.

Meanwhile, warm small pot of lemon juice and gelatin on low heat and set aside after 2 minutes when mixture is clear.

When eggs are done whipping, by hand, fold whipping cream.

Use low speed and pour gelatin into egg mixture and quickly mix.

In a 9 inch springform round pan, lay sponge cake on the bottom and into the middle of the springform pan.

Pour mousse on top of the sponge cake where the mousse pours over the edge of the cake. Continue to pour the mousse across the top of the sponge cake.

Place mousse cake in the springform pan into refrigerator for 4 hours (or overnight if possible, cover with a large plate or lid so a hard skin does not form on the surface).

When ready to serve, use a blow dryer on high temperature to warm the outer ring of the spring form pan. Heat the springform pan all around. Open and release the springform pan and lift the edges.