This homemade version of the Little Debbie cookies are chock-full of real oats and studded with nuts and raisins. The cream filling is a simple cream cheese frosting that's just sweet enough. Keep the cookies in the fridge in an airtight container so that the filling stays firm, but let them stand at room temperature for a few minutes before eating.
Make the cookies: Position racks in the upper and lower thirds of the oven and preheat to 350 degrees F. Line 2 baking sheets with parchment paper.
In a medium bowl, whisk together the oats, flour, cinnamon, baking powder, salt and baking soda.
In a large bowl, beat the butter and sugars together with an electric mixer on medium speed until light and fluffy, about 3 minutes. Add the egg and vanilla and beat to combine. Beat the flour mixture into the butter mixture. Fold in the raisins and walnuts.
Scoop the dough in 2-tablespoon scoops onto the prepared baking sheets, spacing them at least 2 inches apart.
Bake on the upper and lower oven racks until the cookies are set and golden brown, 12 to 14 minutes, rotating the sheets halfway through. Transfer the baking sheets to wire racks and let the cookies cool completely.
Meanwhile, prepare the cream: In a large bowl, beat the cream cheese and butter together with an electric mixer on medium speed until smooth and creamy, about 2 minutes. Beat in the sugar on low speed, then beat in the vanilla extract and salt. Transfer half of the cookies, flat-side up, to a work surface and top each with some of the cream filling, then top with another cookie flat-side down. Refrigerate the cookies for 20 minutes to firm up the cream filling before serving.