Preheat oven to 350 degrees. Spray the bottom and sides of 2 8” cake pans with baking spray and line bottoms with parchment paper.

In a medium bowl mix together the flour, sugar, baking powder, baking soda and salt.

In a large bowl whisk together the eggs, oil and lime juice until smooth. Add the sour cream and whisk until smooth.

Add the flour mixture to the eggs and fold in until no streaks of flour remain. Be careful not to over mix the batter. A few lumps may remain.

Stir in a few drops of green food coloring if desired.

Pour the batter into the prepared pans and bake for 20-25 minutes until done.

Cool in the pans for 10 minutes before turning out to cool completely

While the cake is cooling make the graham cracker crumb.

Preheat the oven to 375 degrees.

Stir together the graham cracker crumbs, melted butter, sugar and salt until well combined.

Turn into a quarter sheet pan and press flat. Bake for 5-7 minutes until set.

Cool in the pan then break into small crumbs.

Beat together the butter and cream cheese for 5 minutes until smooth and creamy, scraping down the bowl once or twice.

Add the powdered sugar and salt, then beat in the vanilla and lime juice.

Beat on high until well combined and a good consistency for spreading. Add a little more powdered sugar if it is too soft.

Split each of the layers into two so you have a total of four layers.

Spread a layer of icing on the first layer and then sprinkle with graham cracker crumb. Make sure to spread the crumb even over the whole layer. Repeat until the top layer goes on.

Spread a thin layer of icing over the sides and top of the cake for a crumb coat. Refrigerate for 30 minutes then spread the rest of the icing over the cake.

Garnish with graham cracker crumbs.