Preheat the oven to 375F. Line a large cookie sheet with parchment paper.
Using a spatula, mix the melted butter and both sugars in a medium bowl.
Add the egg and yolk and mix. Add the extracts and mix until homogenous.
Add the flours, baking soda, and salt. Fold to combine; the dough will be thick.
Dollop the lemon curd in 1/2-tablespoon portions into the dough, then dollop the fluff the same way. Swirl a knife through the dollops and dough to create a marbled effect.
Scoop the cookies with a 2 oz scoop, trying to catch some curd and fluff at the top of each. As you scoop, re-layer some curd and fluff so every scoop has some. Place on the parchment-lined sheet and freeze for 2 hours.
Remove from the freezer and bake 10 to 13 minutes. Let cool 10 minutes, then top with extra curd and fluff if you like.