Creating the Rainbow Lemon Volcano is an enjoyable process that will leave your kitchen filled with delightful aromas. Follow these steps to ensure your success:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Mix Butter and Sugar: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
3. Add Eggs: Beat in the eggs one at a time, ensuring each one is fully incorporated before adding the next.
4. Combine Wet Ingredients: Stir in the buttermilk, lemon zest, and lemon juice until well blended.
5. Blend Dry Ingredients: In another bowl, whisk together the flour, baking powder, and salt.
6. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, mixing until just combined. Be cautious not to overmix.
7. Separate Batter: Divide the batter evenly into five bowls.
8. Color the Batter: Add different food coloring to each bowl to create vibrant layers (red, orange, yellow, green, blue).
9. Layer the Batter: Starting with the red batter, scoop one color into the center of each prepared cake pan. Repeat with each color, allowing the batter to spread outwards naturally.
10. Bake: Place in the preheated oven and bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean.
11. Cool: Once baked, allow the cakes to cool in the pans for 10 minutes before transferring to wire racks to cool completely.
12. Fill the Center: Once cooled, slice the tops off gently to create a flat surface. Place one layer of cake on a serving plate, spread lemon curd in the center, and layer the second cake on top.
13. Decorate: Optionally, frost the top and sides with whipped cream for an elegant finish.

By carefully following these steps, you will create a stunning and delicious Rainbow Lemon Volcano that is sure to amaze!