Coconut Cream Filled Macaroons

Merry Christmas! I can't believe it is already over. It seems like yesterday, or last week, that I was up to my elbows in flour and butter. Mind, I really need to stop eating everything and anything sweet. It is getting bad.
Speaking of bad.. Meet coconut cream filled macaroons. They are oh so coconut-y. It doesn't help that they have a chewy center, slightly crisp edges and that nice creamy filling. Like I said, bad.

Coconut Cream Filled Macaroons
These lovelies adapted from Martha Stewart's Cookie Book!

cookies
3 cups unsweetened medium shredded coconut
1/2 cup sugar
2 or 3 large egg whites*
1 teaspoon coconut extract
1/8 teaspoon coarse salt
filling
2 tablespoons unsalted butter, softened
2 tablespoons cream of coconut, or unsalted butter, softened
1/4 cup vegetable shortening
3/4 cup confectioners’ sugar
1 teaspoon coconut extract

cookies: Stir together coconut, granulated sugar, egg whites, coconut extract and salt in a medium bowl. Refrigerate, covered, until cold, at least 1 hour or overnight (so helpful). Preheat oven to 325 degrees. Form heaping teaspoons of dough into balls; space 1 1/2 inches apart on baking sheets lined with parchment paper. Gently flatten to about 1 1/2 inches in diameter. Bake cookies, rotating sheets halfway through, until edges begin to turn golden, 9 to 10 minutes. Transfer cookies to wire racks and let cool completely.
filling: Put butter, cream of coconut and shortening in a bowl and mix until nice and smooth about a minute or so (or use an electric mixer fitted with the paddle attachment, mix on medium speed until smooth, about a minute). Add confectioners’ sugar and coconut extract; mix until pale and fluffy, about 2 minutes.
assemble: Place a heaping teaspoon filling on the bottom of 1 cookie. Sandwich with another cookie. Repeat with remaining cookies and filling. Transfer to a tray and cover with plastic wrap. Refrigerate until filling is firm, about 30 minutes to an hour. Let stand at room temperature 10 minutes before serving. Cookies can be stored between layers of parchment in airtight containers at room temperature up to 3 days.
* I have made these cookies a few time and the first time around I used two egg whites. However, this time the coconut just wasn't holding together so I threw in another egg white. This may have been a result of staying in the fridge overnight, I'm not sure.

Question, I received two baking cookbooks for Christmas (Babycakes by Erin Mckenna and All Cakes Considered by Melissa Gray) and I was wondering if anyone had a suggestion on what to try first.