Homemade Oatmeal Cream Sandwiches

1. Prepare the Oven and Baking Sheets

Adjust your oven rack to the middle position and preheat the oven to 400 degrees F. Line two rimmed baking sheets with parchment paper.

2. Mix Dry Ingredients

In a medium bowl, whisk together the all-purpose flour, table salt, and baking soda.

3. Process Oats and Raisins

In your food processor, combine the old-fashioned rolled oats and raisins and process them for about a minute until they are finely ground.

4. Combine Wet Ingredients

In a large bowl, whisk together the dark brown sugar, granulated sugar, vegetable oil, melted butter, molasses, and ground cinnamon until the mixture is smooth and well-combined. Add the large egg, large egg yolk, and vanilla extract, and whisk again.

5. Combine Wet and Dry Ingredients

Stir the flour mixture into the wet ingredients using a wooden spoon or spatula until just combined. Then, stir in the oat and raisin mixture until the dough stiffens and all ingredients are evenly distributed.

6. Shape and Bake Cookies

Divide the dough into 24 equal portions, about 38 grams each. Roll each portion into a smooth ball and place them on the prepared baking sheets, spacing them evenly. Flatten each ball into a 2.5-inch-wide disk. Bake the cookies for 5 to 7 minutes per sheet, until the tops begin to crack at the edges. Cool cookies on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.

7. Prepare the Filling

In your food processor, combine the Fluff brand marshmallow crème, confectioners' sugar, softened butter, vanilla extract, and table salt. Process for about 30 seconds until smooth and fluffy.

8. Assemble the Sandwiches

To assemble the sandwiches, spread a scant tablespoon of the filling onto the flat side of one cookie. Top with another cookie to form a sandwich. Repeat with the remaining cookies and filling.