For the Cookies:
1 and 1/4 cups (6 1/4 ounces) all-purpose flour
1/2 teaspoon baking soda
1/2 teaspoon ground cinnamon
1/4 teaspoon salt
10 tablespoons (1 1/4 sticks) unsalted butter, softened to room temperature
1/2 cup (about 4 1/2 ounces) dark brown sugar, firmly packed
1/4 cup (about 1 3/4 ounces) sugar
3/4 cup creamy unsalted peanut butter
2 large eggs, lightly beaten
2 teaspoons vanilla extract
1/2 cup quick oats

For Assembly:
1/2 cup creamy unsalted peanut butter
1/2 cup marshmallow cream