• Preheat the oven to 350 degrees and grease cake pans with baking spray, set aside.
• In a large bowl, combine the flour, baking soda, baking powder and salt.
• Using a standing mixer, cream the butter and sugar until light and fluffy.
• Beat together the egg whites and vanilla until combined. Gradually beat in the flour ingredients and milk until combined. Beat in the lime juice, tequila, and lime zest until combined.
• Divide the batter between the 3 cake pans.
• Bake in the oven for 25-30 minutes or until a tooth pick comes out clean. Allow the cakes to cool completely.

Frosting

• Using a standing mixer, combine all ingredients into the mixer and beat until combined, smooth and stiff with peaks.
• Scoop 1 cup of frosting into the piping bag and set aside.

Decorating

• Using the cake leveler, remove the domes from the cakes to level them out.
• Place one cake round onto the cake board. Scoop 1 cup of frosting onto the cake and smooth evenly.
• Place the second cake round onto the top of the frosting. Scoop 1 cup of frosting onto the second cake layer and smooth evenly.
• Place the last cake round onto the top of the frosting. Using the remaining frosting, frost entire cake.
• Pipe dollops of frosting onto the top of the cake. Place Lime slices onto the frosting. Zest a lime all over the top of the cake.
• Place into the fridge for an hour to allow the frosting to harden up a bit.