Preheat the oven to 350F. Line two baking sheets with parchment or silicone liners.
In a large bowl or the bowl of a stand mixer, beat together the butter, brown sugar, and sugar until well combined. Add the egg, egg yolk, and vanilla, and mix until combined.
Add the flour, baking soda, and salt, and mix until just combined. Fold in the chocolate chips, coconut, and pecans. Scoop the dough into one inch balls, then divide the balls in half and stack the two halves on top of each other like a snowman. Sprinkle with additional coconut if desired.
Bake 12-14 minutes, or until the cookies are just slightly browned on top and around the edges. Let cool five minutes before removing to a cooling rack.