Preheat oven to 375°F. Line a 9x13 baking pan with foil and spray with nonstick spray. Set aside.

Using a hand mixer or stand mixer, beat butter and sugar for several minutes, until light and fluffy. Add egg, egg white, sour cream and extracts and beat until thoroughly combined, scraping the sides of the bowl as needed. The mixture might look slightly curdled.

In a separate bowl, combine flour, baking powder, salt and ½ cup coconut. With your mixer on low, add flour to the butter mixture, mixing until just combined, being careful not to over mix. The dough will be thick.

Dump the dough into the prepared pan and use your fingers to evenly press it into the pan. I moisten my fingers with a little water to help make pressing the dough into the pan a little easier. Bake for about 15 minutes, until the top appears dry and the edges are just starting to turn light brown. Rotate the pan halfway through the baking time. Make sure not to over bake these, as they will continue to cook a little after you remove them from the oven. When you remove them from the oven they should not be completely done. Place the pan on a rack to cool completely before frosting them.

Using a hand mixer or stand mixer, beat butter and cream cheese until smooth and creamy. Add powdered sugar and beat to combine. Add half and half and extracts and beat on low speed until combined. Increase speed to high and beat for another minute or two, until light and fluffy. Use an offset spatula or butter knife to spread the frosting over the bars. Top with 1 cup shredded coconut (toasted and cooled, if desired). Cut into bars. Store and serve at room temp.