The Bojon Gourmet

0 Position a rack in the center of the oven and preheat to 350º. Put sling of parchment paper or heavy aluminum foil in an 8x8" square baking pan, or grease the pan.
1 Spread the pecans on a small sheet pan and roast in the oven until golden and fragrant, 10 - 12 minutes. Remove and let cool, then break or chop into coarse pieces.
2 Meanwhile, spread the coconut on another small baking pan and bake for 5 minutes until golden, stirring once or twice. Set aside to cool.
3 In a large bowl, whisk together the sugar and egg. Slowly pour in the melted butter, whisking to combine, and add the rum and vanilla.
4 In a small bowl, whisk or sift together the flours, xanthan gum, baking powder and salt. Stir the dries into the wets. Stir in the cooled pecans, coconut, and chocolate chunks.
5 Spread the dough evenly into the parchmented pan. (It will look like not enough, but don't worry, it will rise in the oven.)
6 Bake until puffed, shiny and slightly cracked on top, and a toothpick inserted comes out with a few large, wet crumbs clinging (don't overbake), 15 - 20 minutes. Let cool at least 20 minutes before cutting (longer for cleaner-looking bars). Trim away the outer 1/2", then cut into 16 bars.
7 The bars are best the day they are made, but will keep, in an airtight container, for several days.