1. Add the eggs one at a time, making sure each is fully incorporated before adding the next. Stir in the vanilla extract.
2. Gradually add the dry ingredients to the wet mixture, alternating with prosecco, elderflower syrup, lime zest, and lime juice. Start and end with the dry ingredients, mixing gently until just combined. Be careful not to overmix.
3. Pour the batter evenly into the prepared cake pans and smooth the tops with a spatula.

Step 2: Bake the Cake

1. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
2. Remove the cakes from the oven and let them cool in the pans for about 10 minutes before transferring them to a cooling rack to cool completely.

Step 3: Prepare the Frosting

1. While the cakes are cooling, prepare the frosting. In a stand mixer, beat the heavy whipping cream until stiff peaks form. Set aside.
2. In a separate bowl, beat the cream cheese until smooth and creamy.
3. Add elderflower syrup, prosecco, powdered sugar, lime zest, and lime juice to the cream cheese mixture. Beat until fully combined and fluffy.
4. Gently fold in the whipped cream, ensuring it maintains the light and airy texture.

Step 4: Assemble the Cake

1. Once the cakes are completely cooled, place the first cake layer onto your cake stand or platter.
2. Spread a generous amount of frosting on top of the first layer, smoothing it out evenly.
3. Place the second cake layer on top and press gently to secure it.
4. Apply a thin crumb coat of frosting around the entire cake to seal in any loose crumbs. Refrigerate the cake for about 15 minutes to set the crumb coat.
5. After the crumb coat has set, apply a thick layer of frosting to the entire cake, smoothing the edges with an offset spatula.

Step 5: Decorate the Cake

1. Garnish the top of the cake with fresh lime slices for a burst of color and citrus fragrance.
2. Optionally, add edible flowers for an elegant touch or drizzle extra prosecco over the top for a sparkling finish.