Preheat oven to 400 degrees. Grease 12 muffin cups.
Combine 3 tablespoons flour, brown sugar, and cinnamon in a small bowl. Use a fork to cut in the butter until the mixture resembles coarse crumbs. Reserve.
Combine 1 3/4 cup flour, white sugar, baking powder, salt, and the instant oatmeal in a large bowl. Make a well in the center of the flour mixture; pour in the egg, milk, and oil. Stir just until moistened. Spoon batter into prepared muffin cups, filling each 2/3 full. Evenly sprinkle topping over muffins.
Bake until toothpick inserted in center of muffin comes out clean, about 15 minutes. Cool on wire rack for 5 minutes before serving.
208 calories; protein 3.9g; carbohydrates 30.9g; fat 7.8g; cholesterol 22.2mg; sodium 202.3mg