CAKE: Heat oven to 350. Mix all ingredients for the cake until well blended. Two minutes on medium speed.Line cupcake pans with paper liners. Scoop (using an ice cream scooper) the batter until 3/4 full. Batter will be thick. Bake 18-20 minutes until touching the center springs back or a toothpick inserted in the center, comes out clean. Cool on wire rack until completely cooled
FILLING/INFUSING: Using a pastry bag with the large tip or large storage bag (cut a small hole at one of the ends) fill the bag with the lemon curd. If using the pastry bag, insert the tip in the middle of the cooled cupcake and squeeze the bag until the curd fills the hole. If using a storage bag, cut a small hole in the cupcake first, then fill the hole with the curd.
FROSTING: Mix the butter, cream cheese until smooth and creamy, add confectioners sugar (small amounts at a time)then extracts until well blended and stiff. More or less sugar may be required, until the consistency is reached. Put frosting in a pastry bag using desired tip and frost. Or frost by hand.
GARNISH: For the coconut garnish, toast the coconut in the oven, flat on a cookie sheet for 4-6 minutes. Let cool, then add on top. Or garnish with the lemon sprinkles.