Key Lime Poke Cake

1 . Stage

Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking pan.

2 . Stage

Combine cake mix, water, eggs, and oil in a large bowl; beat with an electric mixer on low speed until moistened. Increase speed to medium and beat for 2 minutes. Pour batter into the prepared baking pan.

3 . Stage

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 24 to 29 minutes.

4 . Stage

Dissolve gelatin mix in boiling water. Add key lime juice and mix well.

5 . Stage

Use a fork to poke holes all over the cake. Spoon gelatin-key lime mixture all over cake. Refrigerate until completely cool and ready to use.

6 . Stage

Meanwhile, whisk eggs and egg yolks together in a large glass bowl. Combine sugar, lime juice, lime zest, and cornstarch in a smaller heat-proof bowl.

7 . Stage

Place bowl with the sugar mixture over a pot of simmering water. Stir frequently, scraping down the sides with a rubber spatula to avoid scorching, until mixture comes to boil, about 5 minutes.

8 . Stage

Slowly whisk hot sugar mixture, little by little, into the beaten eggs. Place bowl over the pot of simmering water and whisk until curd coats the back of a spoon, up to 10 minutes. Remove from heat; mix in butter until melted.

9 . Stage

Drop food coloring into the curd and mix to achieve your desired shade. Let cool to room temperature, at least 30 minutes. Cover surface directly in plastic wrap and refrigerate until completely cool, about 2 hours.

10 . Stage

Transfer 3/4 of the curd into another bowl. Add whipped topping and fold together until well combined. Spread frosting over the cake. Refrigerate until set, at least 2 hours more. Top with the plain curd.