Preheat your oven to 350°F. Grease a 9-by-13-inch baking pan with butter or cooking spray, then lightly flour it or line the bottom with parchment paper.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Mixing these ingredients separately helps distribute the leavening agents evenly throughout the cake.

Measure the buttermilk, shred or measure the coconut, and chop the pecans. Having everything ready before mixing helps the batter come together smoothly.

For the best results, allow the butter, eggs, and buttermilk to reach room temperature. Cold ingredients can cause the butter mixture to look curdled and may make it harder to achieve an even batter.

Step 2: Cream the Butter and Sugar

Place the softened butter and granulated sugar in a large mixing bowl. Using a hand mixer or stand mixer, beat them together for approximately 3–4 minutes, until the mixture looks pale and fluffy.

This step helps incorporate air into the batter, contributing to the cake’s texture. Scrape down the sides and bottom of the bowl occasionally so the ingredients mix evenly.

Add the eggs one at a time, beating after each addition. Stir in the vanilla extract.

If the mixture looks slightly uneven after adding the eggs, do not worry. Scrape the bowl and continue mixing gently until the ingredients are mostly combined.

Step 3: Combine the Batter and Add Coconut and Pecans

Add about one-third of the dry ingredients to the butter mixture and mix on low speed until just combined. Add half of the buttermilk, then another portion of the dry ingredients.

Continue alternating the remaining buttermilk and flour mixture, finishing with the dry ingredients. Mix only until no large streaks of flour remain.

Fold in the shredded coconut and chopped pecans using a spatula. Avoid overmixing, because excessive mixing after adding flour can make the cake dense.

The finished batter should be thick but spreadable, with coconut and pecans distributed throughout.

Step 4: Bake the Cake

Transfer the batter to the prepared pan and spread it evenly into the corners. Smooth the surface with a spatula.

Bake for approximately 35–45 minutes, checking toward the earlier end of the range. The cake is ready when the top is golden, the center springs back lightly when touched, and a toothpick inserted into the middle comes out clean or with a few moist crumbs.

If the top browns too quickly, loosely cover it with aluminum foil during the final part of baking.

Remove the pan from the oven and place it on a cooling rack. Let the cake cool completely before adding the frosting. Applying frosting while the cake is warm can cause it to melt and slide off.

Step 5: Make the Coconut Pecan Frosting

In a medium saucepan, combine the butter, evaporated milk, granulated sugar, and egg yolks. Whisk thoroughly before turning on the heat so the egg yolks are evenly distributed.

Cook over medium-low heat, stirring constantly with a heat-resistant spatula or whisk. Continue cooking for approximately 8–12 minutes, or until the mixture thickens enough to coat the back of a spoon.

Do not let the mixture boil vigorously, and do not leave it unattended. The egg yolks need to cook thoroughly, and constant stirring helps prevent scorching or curdling.

Remove the saucepan from the heat and stir in the vanilla, shredded coconut, and chopped pecans. Allow the frosting to cool until it thickens to a spreadable consistency.

Spread the frosting evenly over the completely cooled cake. Let it settle for 15–20 minutes before slicing.

For clean slices, use a sharp knife and wipe it between cuts. Serve at room temperature for the best buttery flavor and tender texture.