1. Preheat oven to 375 degrees Fahrenheit and fill cupcakes pans with liners.
2. Sift the flour, baking powder and half the sugar together into a large mixing bowl and reserve.
3. In another large mixing bowl combine the egg yolks, oil, water, vanilla and zest. Mix with beaters until thoroughly combined, about 1 minute. Add the egg yolk mixture gradually to dry ingredients mixing with beaters on medium speed until a past forms. When a paste has formed scrape down the sides of the bowl and continue adding the remainder of the yolk mixture until it is all incorporated. Beat for an additional 2 minutes on medium speed.
4. In a separate mixing bowl whip the egg whites with a clean beater on medium speed until soft peaks form. Gradually add the remaining sugar while beating the egg whites and continue to beat until medium peaks form.
5. Gently blend one-third of the beaten egg whites into the egg yolk mixture to lighten it. Gently fold in the remaining egg whites.
6. Divide the batter evenly among the prepared pans.
7. Bake for about 20 minutes, until the top of the cupcakes spring back to the touch. Let cool in the pans for a few minutes before cooling on a wire rack.
8. Prepare Lemon Curd filling and Swiss Butter cream frosting. Fill a piping bag with lemon curd, insert the tip as far as it will go inside the center of the cupcake and apple pressure, stop filling when you see any lemon curd around the tip of bag. Clean the tip and piping bag and fill it 2/3 full with frosting. Pipe a large pearl of frosting on each cupcake and use the back of a spoon to lift up areas creating spikes. Lightly toast the meringue with a kitchen torch or under the broiler until the tips are golden brown.