1-First Step: Preparation Before you begin, preheat your oven to 350°F (175°C). Proper oven temperature is crucial for even baking. Grease two 8-inch round pans with butter or cooking spray, then dust with flour to prevent sticking. You can also line the bottoms with parchment paper for easy removal later. Gather all your ingredients and measuring tools to ensure a smooth cooking process. Having everything ready before you start is the secret to stress-free baking.

2-Second Step: Mixing Dry Ingredients In a medium bowl, whisk together 2 cups all-purpose flour, 1.5 teaspoons baking powder, and 0.5 teaspoon salt. Whisking these dry ingredients together ensures that the leavening agent is evenly distributed throughout the flour, which helps the cake rise uniformly. Set this mixture aside while you prepare the wet ingredients. This separation of wet and dry ingredients is a fundamental technique in cake baking that prevents overmixing later in the process.

3-Third Step: Creaming Butter and Sugar In a large bowl, beat 1 cup softened butter with 1.5 cups sugar until fluffy and pale. This process, known as creaming, incorporates air into the batter, resulting in a lighter cake texture. Use a stand mixer or hand mixer on medium-high speed for about 3-5 minutes. You’ll know it’s ready when the mixture has noticeably increased in volume and looks creamy. Then add 4 eggs one at a time, beating well after each addition. This gradual incorporation helps maintain the structure you’ve created through creaming. Finally, mix in 0.25 cup lime juice and 1 tablespoon lime zest until combined.

4-Fourth Step: Combining Ingredients With the mixer on low speed, add the dry ingredients to the butter mixture in three additions, alternating with 0.75 cup milk in two additions (beginning and ending with the dry ingredients). Mix only until just combined after each addition. Overmixing at this stage can develop gluten, resulting in a tough cake. The batter should be smooth but not overworked. Gently fold in any remaining dry ingredients at the bottom of the bowl with a spatula to ensure everything is incorporated without excessive mixing.

5-Fifth Step: Baking the Cake Divide the batter evenly between your prepared pans. You can use a kitchen scale for precision or estimate by eye if you don’t have one. Tap the pans gently on the counter to release any air bubbles. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. The edges should start to pull away from the sides of the pan, and the tops should spring back when lightly touched. Rotate the pans halfway through baking for even results.

6-Final Step: Finishing Touches and Serving Allow the cakes to cool in the pans for 10 minutes, then turn them out onto wire racks to cool completely. This cooling period is essential if you try to frost a warm cake, the frosting will melt and slide off. Once completely cooled, make your lime buttercream by beating 0.5 cup butter until creamy, then gradually adding 3 cups powdered sugar, 2 tablespoons lime juice, and 1 teaspoon lime zest until smooth. Frost between the layers and over the top and sides of the cake. Garnish with additional lime zest or fresh lime slices for a beautiful presentation. This moist key lime cake is best served at room temperature but can be refrigerated for longer storage.