Preheat oven
Preheat to 375°F. Line baking sheets with parchment paper.
Mix dry ingredients
In a medium bowl, whisk together:
gluten-free flour
baking powder
baking soda
salt
cinnamon
cornstarch
Set aside.
Cream butter and sugars
In a large bowl, beat butter, brown sugar, and granulated sugar until light and fluffy, about 2–3 minutes.
Add eggs and vanilla
Mix in eggs one at a time, then stir in vanilla until fully combined.
Combine wet and dry
Add the dry ingredients to the wet ingredients and mix just until combined. Do not overmix.
Stir in oats and chocolate chips
Fold in oats until evenly distributed, then stir in chocolate chips.
Chill the dough
Cover and refrigerate for at least 30–60 minutes (or up to overnight for best texture).
Bake
Scoop dough (about 2 tablespoons each) onto baking sheets
Space cookies about 2 inches apart
Bake for 10–12 minutes, until edges are set and lightly golden while centers remain soft.
Cool
Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rac
See FAQ's for gluten-free flour options