Preheat oven to 350 degrees F. Place racks in the upper and lower thirds of oven. Place the chopped pecans on a baking sheet and toast in the oven for about 7 minutes until fragrant and toasty. Let cool.
Next, in a blender, grind up 3/4 cup of the oatmeal and create oat flour. Let it blend until super fine. Sift through a fine sieve into a bowl. Discard all the big pieces. You’ll wind up with about 1/2 cup of flour. In a bowl, mix the brown sugar substitute, melted butter, vanilla, salt and cinnamon until combined. Whisk in the egg, then add the baking soda, xanthan gum, and oat flour. Whisk vigorously for about one minute. (Unlike flour that has gluten, you do want to work gluten-free recipes using xanthan gum. They need a good “beating” to help thicken the mixture.)
Add pecans, chocolate chips, cherries and the 1 1/2 cups of oats into the batter. Cover and let sit for about an hour to let the oats absorb all the liquid.
Using an ice cream scoop or 1/4 cup measuring cup, scoop the batter onto parchment-lined baking sheets. Leave 2 inches between each cookie (they spread). Gently press the cookies down with a fork, keeping the round circles. Sprinkle with the flaky salt.
Bake, rotating pans halfway through the bake, until golden brown around the edges, 10-12 minutes. The middle will still look unbaked.
Remove from the oven and gently nudge the edges into a nice round circle with the back of a spoon. This will just make the cookies uniform in size and shape and is completely optional! Let rest on the baking sheet for 10 minutes then transfer to a rack and cool completely. ENJOY!