1-Preheat your oven: Preheat your oven to 350°F and line your baking sheets with parchment paper to keep everything from sticking and help with even baking.

2-Cream together butter and sugars: In a large bowl, cream together 1 cup softened unsalted butter, 3/4 cup firmly packed light brown sugar, and 1/2 cup granulated sugar until it’s light and fluffy, which takes about 3 minutes with a mixer.

3-Add eggs and vanilla: Add 2 large eggs and 1 teaspoon pure vanilla extract to the mixture, beating until everything is fully combined for that smooth base.

4-Whisk dry ingredients: In another bowl, whisk together 1 1/2 cups all-purpose flour, 1 teaspoon baking soda, 1 teaspoon ground cinnamon, and 1/2 teaspoon salt until well mixed.

5-Combine wet and dry ingredients: Slowly add the dry ingredients to the wet ones, stirring just until combined, then mix in 3 cups quick or old-fashioned oats thoroughly.

6-Drop dough onto sheets: Use a large cookie scoop (about 3 tablespoons) to drop dough onto the sheets for big cookies or a medium scoop (1.5 tablespoons) for smaller ones, spacing them about 2 inches apart.

7-Bake the cookies: Bake the large ones for 13-15 minutes or the small ones for 10-12 minutes, until the edges are golden but the centers stay soft trust me, that’s the key to chewiness.

8-Cool the cookies: Let the cookies cool on the sheets for 5 minutes, then move them to a wire rack to cool completely before adding the filling.

9-Prepare the cream filling: For the filling, beat 3/4 cup softened unsalted butter on medium-high speed for 5 minutes until it’s fluffy and light. Gradually add 2 1/2 cups sifted confectioners’ sugar, then mix in 1 teaspoon pure vanilla extract and 1 tablespoon milk or half and half. Beat it for another 3-5 minutes to get that perfect consistency, adjusting with a bit more milk if it needs to be softer.

10-Assemble the oatmeal cream pies: Assemble by spreading or piping the filling onto the flat side of half the cookies and topping with the others. For the best fluffy buttercream tips, visit this expert frosting guide.