Ingredients
- 1 cup unsalted butter softened
- 1 cup light brown sugar packed
- 1/2 cup granulated sugar
- 2 large eggs
- 1 teaspoon vanilla extract
- 1 1/2 cups all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 teaspoon ground cinnamon
- 3 cups quick oats
- 3/4 cup unsalted butter softened (for filling)
- 3 cups powdered sugar
- 1 teaspoon vanilla extract for filling
- 2 tablespoons heavy cream or more as needed
Instructions
- Preheat oven to 350°F and line baking sheets with parchment paper.
- In a large bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy. Add eggs and vanilla, mixing well.
- Whisk together flour, baking soda, salt, and cinnamon. Gradually add to the creamed mixture, mixing well. Stir in oats.
- Drop tablespoonfuls of dough onto prepared sheets, spacing them 2 inches apart. Bake for 10-12 minutes, or until golden brown. Cool on wire racks.
- For the filling, beat 3/4 cup butter until smooth. Gradually add powdered sugar and vanilla, then cream until light and fluffy. Adjust thickness with heavy cream.
- Spread filling on the flat side of half the cookies; top with remaining cookies to form sandwiches.