1. Preheat oven to 350°F and prepare three 8 inch round cake pans by lining the bottoms with parchment and greasing the sides.

2. Beat sugar, oil, eggs, and vanilla together until smooth and fully combined, then mix in sour cream until the batter becomes creamy.

3. In a separate bowl whisk together flour, baking powder, and salt.

4. Add lime zest to the batter and gradually combine the dry ingredients with the wet mixture while alternating with lime juice, tequila, and milk until a smooth batter forms.

5. Divide batter evenly between the prepared pans and bake until the cakes are set and a toothpick inserted in the center comes out clean, about 23 minutes.

6. Cool the cakes in the pans briefly, then remove and allow them to cool completely on a rack.

7. For the frosting, heat egg whites and sugar over a double boiler while whisking constantly until the sugar dissolves and the mixture reaches about 140 to 150°F.

8. Transfer the mixture to a mixer and whip until thick, glossy peaks form and the meringue cools to room temperature.

9. Add softened butter gradually while mixing until a smooth buttercream forms, then blend in the puréed strawberries and lime zest until evenly incorporated.

10. Level the cooled cake layers if necessary.

11. Place the first layer on a serving plate, spread frosting over the top, add the second layer and repeat, then place the final layer on top.

12. Cover the entire cake with the strawberry Swiss meringue buttercream and decorate as desired before slicing and serving.