1tablespoonfresh lime zest, from about 2-3 medium limes
1large egg yolk
¼cupfresh lime juice
½ to 1teaspooncoconut extract
½cup(113g)salted butter, melted and cooled a bit
1tablespoonfresh lime juice
½teaspoonfresh lime zest
Toasted coconut, for topping
Preheat the oven to 350 degrees F. Line an 8X8-inch aluminum baking pan with parchment so that it hangs over two of the edges (to lift out the bars later - alternately, you can just grease the pan really well and slice them in the pan) and lightly coat the pan and parchment with nonstick cooking spray.
In a large bowl, whisk together the flour, sugar, salt, baking powder and lime zest.
In a separate bowl or in a large liquid measuring cup, whisk together the eggs and egg yolk, lime juice, vanilla extract and coconut extract.
Add the butter to the dry ingredients followed by the egg/lime juice mixture; mix until combined and no dry streaks remain.
Spread the batter evenly in the prepared pan.
Bake for 18-20 minutes until a toothpick inserted in the center comes out clean or with moist crumbs (the top of the bars should spring back lightly when gently pressed). Don't over bake or they might be dry.
For the glaze, whisk together the powdered sugar, sour cream, lime juice and lime zest until well combined.
After the bars have cooled completely in the pan, drizzle the glaze over the top (since the glaze layer is thin, it helps to pour it all across the bars instead of in one puddle before spreading) and use an offset spatula or knife to spread evenly over the bars. Sprinkle toasted coconut over the top.
Place the bars in the refrigerator for 1-2 hours to let the glaze set before lifting them from the pan (using the parchment overhang) and cutting into small squares. These taste best chilled, in my opinion, but can be served at room temperature also.
Limes: you'll need about 3 medium/large limes for this recipe (you'll use both the zest and juice so make sure to zest them before juicing).