Preheat the oven to 350℉ Line a baking sheet with parchment paper.
In a mixing bowl, combine the flour, oatmeal, baking soda, cornstarch, salt, and cinnamon. Set aside.
In a mixer or by hand, cream the butter and sugar for about 3-5 minutes or until creamy. Then mix in the beaten egg and vanilla extract until well combined.
Slowly add in the flour until a dough forms.
Fold in the blueberries and chocolate chips.
Drop the dough onto the baking sheet by the spoonful an inch apart from each other. Bake in the oven for 12 minutes.
Remove from the oven and let the cookies sit on the baking sheet for another 5 minutes. Serve once cooled.
Store in the refrigerator in a sealed container for 3-5 days.
