Oatmeal Cream Pie Cookies

For the cookies:

1. Whisk melted butter with both sugars until smooth. Add eggs and vanilla.
2. Stir in flour, baking soda, salt, and cinnamon until almost combined.
3. Mix in oats until dough comes together.
4. Let dough sit 10–15 minutes so the oats absorb moisture.
5. Scoop 1-tablespoon portions onto a lined baking sheet. Chill 15–20 minutes.
6. Bake at 350°F for 13–15 minutes until edges are set and centers are soft.
7. Cool completely before filling.

For the Maple Vanilla Filling:

Beat softened butter, powdered sugar, maple syrup, vanilla, a pinch of salt, and 1-2 tsp milk or cream (as needed) together until light and fluffy. Pipe onto one cookie and sandwich with another.