How to Make It
Heat oven to 350° F. Toast the coconut on a baking sheet, tossing occasionally, until golden, 10 to 12 minutes. Butter two 8-inch round cake pans. In a large bowl, whisk together the flour, baking powder, and salt.
Using an electric mixer, beat the butter and granulated sugar until fluffy. Beat in the eggs one at a time, then the vanilla and ¾ cup of the preserves. Alternately add the flour mixture and the milk, mixing just until incorporated.
Divide the batter between the pans and bake until a toothpick inserted in the centers comes out clean, 40 to 45 minutes. Remove the cakes from the pans and let cool completely on racks.
Using an electric mixer, beat the heavy cream, sour cream, and confectioners' sugar until stiff peaks form. Spread the remaining ½ cup of preserves on top of one of the cakes; sandwich with the other. Frost with the cream mixture and press the coconut onto the sides.