In a medium saucepan, combine egg yolks and sugar. Whisk together until smooth.

Place the saucepan over medium-low heat and whisk in the lime juice, mint sprig, and zest. 

One combined, add in the butter. Whisk constantly to incorporate the butter.

Continue to whisk the mixture frequently until it thickens, about 7 minutes.

The curd is ready once it holds the marks of a whisk or coats the back of a metal spoon.

Transfer the curd to a jamming jar or bowl and cover tightly with plastic wrap. Allow it chill in the refrigerator until cool and set, at least 2 hours. 

While the curd is setting, you can bake the cake. This way everything will be ready around the same time!

Preheat the oven to 350°F and prepare 2 9-in round cake pans by spraying with cooking spray and then covering with parchment paper. This will keep the cake from sticking to the pan. 

In a medium bowl, combine the flour, baking salt, lime zest and mint

In the bowl of a stand mixer, combine the butter, sugar, and vegetable oil. Beat until light and fluffy.

Add the eggs one at a time, beating until combined after each addition. 

Add the lime juice and greek yogurt, and beat until combined. 

With the mixer on low, slowly add in the dry ingredient mixture that you set aside. Beat until a batter is formed. It will be a thick batter. 

Separate the mixture evenly into the two cake pans. Using a spatula, smooth the tops of the batter to create an even layer. Bang the bottoms of the cakes on the counter to remove the air bubbles. 

Bake for 35-40 minutes, or until a toothpick or cake tester inserted into the middle of the cakes comes out clean. While the cakes are baking, you can make the soak. 

When the cakes are ready, remove them from the oven and allow them to cool slightly in the pans. 

While they are still warm, turn the cakes out onto cooling racks. 

Brush the cakes (tops and sides) with the glaze. Do one layer and allow it to soak in and then do another layer of soak. 

In a small saucepan, combine the lime juice, sugar, and mint. 

Cook over medium-low heat, stirring constantly, until the sugar is dissolved. Remove from heat.

In the bowl of a stand mixer, combine the egg whites and sugar. 

In a small pot, bring some water to a simmer. You will place the stand mixer bowl over the simmering water, so you don't want the bowl and the water to touch. 

Once the water is simmering, place the bowl with the eggs and sugar over the simmering water. 

Whisk vigorously until the sugar is completely dissolved - about 5 minutes. 

Move the bowl to the stand mixer.

With the whisk attachment, beat the egg mixture on the highest speed until completely cool - about 10 minutes. It should be glossy and thick - and almost look like melted marshmallows. 

Once the egg mixture is completely cool, add the butter. Add it one tbsp at a time, until the mixture is thick and creamy. Wait for each tbsp of butter to be incorporated before you add the next one. 

Once the butter is fully incorporated, turn off the stand mixer. Use a spatula to remove anything from the sides of the bowl and anything from the bottom that may not be fully incorporated.

Turn the mixer back onto the highest speed and beat for 1 minute to combine. 

Add the mint, lime zest, and lime juice. Beat until combined.

Transfer to a piping bag and get ready to frost your cake!

At the center of the cake stand, place a little bit of frosting. This will hold the cake in place while we assemble it. 

Put the first cake down on the stand, the smooth side on the bottom. 

Pipe a thick circle of frosting on top of the cake all the way at the edge. This will create a wall, so the curd does not ooze out of the sides of your cake. 

Fill the remainder of the circle with the set curd. 

Place the second cake on top, this time with the flat side facing up. This will help your cake have a very smooth appearance. 

Cover the top of the cake with frosting and use a spatula to smooth the layer. 

I chose to leave the sides of the cake naked, but you can cover the whole thing with frosting if you would like! Decorating is the time to go a little off book!!

Enjoy!