8ozcoconut milk or cream of coconutshake well if refrigerated
1 1/2teaspoonscoconut extractfor the batter
1cupsour cream, room temperature
Frosting Ingredients
1/4cupunsalted butter, softened to room temperature
8ozcream cheese, softened to room temperature
1 1/2teaspoonscoconut extractoptional, for the frosting
1teaspoonvanilla extract
1ozcoconut milkfor frosting — approximately 2 tablespoons
4cupspowdered sugar, sifted if clumpy
1 to 2cupsshredded coconutfor garnish; sweetened or unsweetened depending on preference
Instructions
Preheat the oven to 350°F (175°C) and grease a 9×13-inch baking pan. Lightly flour or line with parchment for easy removal.
In a large mixing bowl, combine the white cake mix, 1/4 cup vegetable oil, 3 large eggs, 8 oz coconut milk, 1 1/2 teaspoons coconut extract, and 1 cup sour cream. Use a hand mixer or stand mixer and beat on medium speed for 4 minutes until the batter is smooth and slightly aerated.
Pour the batter into the prepared 9×13 pan and spread it into an even layer with a spatula. Tap the pan gently on the counter to release any large air bubbles.
Bake for 30–35 minutes, rotating the pan halfway through if your oven has hot spots. Check doneness with a toothpick inserted in the center — it should come out clean or with a few moist crumbs.
Remove the cake from the oven and let it cool completely in the pan on a wire rack before frosting. Cooling fully prevents the frosting from sliding off.
For the frosting, beat together 1/4 cup softened unsalted butter and 8 oz softened cream cheese until smooth and creamy. Add 1 1/2 teaspoons coconut extract (if using), 1 teaspoon vanilla extract, and 1 oz coconut milk. Beat until well combined.
Gradually add 4 cups powdered sugar, about 1 cup at a time, beating on low between additions until incorporated, then increase speed and beat until light and fluffy. If the frosting is too thick, add a teaspoon of coconut milk at a time to reach spreading consistency.
Spread the frosting over the cooled cake using an offset spatula. Sprinkle 1 to 2 cups shredded coconut evenly over the top. For added flavor, toast the shredded coconut in a dry skillet over medium heat for 2–4 minutes until golden, stirring constantly, then cool and sprinkle on top.
Notes
Store the frosted cake covered with a cake dome or airtight container in the refrigerator for up to 4 days. The cream cheese frosting must be refrigerated.