In a medium bowl, whisk both sugars with the coconut oil and lemon zest until smooth. Whisk in the egg and vanilla extract until incorporated. With a rubber spatula, stir in the flour blend, baking soda, salt and cinnamon until smooth. Stir in the oats and blueberries until combined. Cover the bowl with plastic wrap and refrigerate for 1 hour.
Position racks in the upper and lower thirds of the oven and preheat it to 350 degrees F. Line two baking sheets with parchment paper.
Portion the dough into twelve 2-ounce portions using a 1/4 cup measure or a 2-ounce cookie scoop. Using your hands, form the dough into pucks. Evenly space 6 of the pucks on each prepared baking sheet.
Bake on the upper and lower oven racks for 14 to 16 minutes, rotating the baking sheets halfway through and swapping the positions on the racks, until the edges of the cookies are golden brown. Let cool on the baking sheets.