There are so many reasons why you might end up with a dry cake! One common reason is that you're not properly measuring your ingredients. For example, if you don't scoop and level your flour, you will add too much, which can cause a dry cake. Another reason is that you're overbaking your cake. When it's done, a cake tester should come out clean, and the cake should be slightly springy to the touch. For a tender, moist coconut cake every time, you want to use a high-fat dairy product like sour cream in the batter. It can also be beneficial to use the reverse creaming method, which will help give your cakes a light texture without overworking the batter!