Preheat the oven to 325° F convection (or 350° F for a regular oven).
Spread the oats out on a baking tray and toast in the oven for about 10 minutes. Let the oats cool completely and then process in a food processor, until powdery.
Spread the coconut out on a baking tray and toast in the oven until golden and crunchy, for about 8 minutes, stirring once or twice. Allow to cool completely.
Beat the butter with sugar until creamy. Stir in the oats, flour, coconut and salt. Mix on low speed until the dough comes together. Scrape the dough out onto a work surface and pat it into two logs, about 1 1/4 inches in diameter. Wrap the logs up in plastic wrap and refrigerate until very firm, at least two hours.
Preheat the oven to 325°F convection (or 350°F regular bake). Slice the dough into 1/4-inch thick slices and arrange on a baking sheet lined with parchment paper. Prick the top of the shortbreads with a fork. Bake for about 20 minutes, or until golden. Slide the parchment onto a wire rack and let the shortbreads cool.
The shortbreads can be kept in an airtight container for about a week.
Aleksandra aka QueenSashy is a scientist by day, and cook, photographer and doodler by night. When she is not writing code and formulas, she blogs about food, life and everything in between on her blog, Three Little Halves. Three Little Halves was nominated for 2015 James Beard Awards and the finalist for 2014 Saveur Best Food Blog Awards. Aleksandra lives in New York City with her other two halves, Miss Pain and Dr. V.