Preheat your oven to 325°F (163°C) and prepare a ¼ sheet pan with parchment paper.

In a medium bowl, whisk together the sour cream, water, vanilla extract, almond extract, and pure coconut extract until smooth.

In a large bowl, sift together the all-purpose flour, Instant Clearjel, baking powder, and salt. Mix with the softened butter until crumbly.

Gradually add the wet ingredients to the dry mixture, mixing on low until smooth. Scrape down the bowl sides as needed.

Beat the egg whites until soft peaks form and gently fold into the batter.

Pour the batter into the prepared pan and bake for 25-28 minutes or until a toothpick inserted comes out clean.

Let the cake cool for 10 minutes, poke holes, and pour cream of coconut over the warm cake.

Cool completely; refrigerate or freeze the cake before frosting.

Frost with vanilla bakery buttercream and sprinkle with toasted coconut flakes.

Allow to sit at room temperature for 30 minutes before serving.