I preheat the oven to 350°F (180°C) and line two baking sheets with parchment paper. In a large bowl, I cream 1 cup softened butter, 1 cup brown sugar, and ½ cup granulated sugar with a mixer on medium-high for 2–3 minutes until fluffy. I add 1 tbsp molasses, 2 tsp vanilla, and 2 eggs, mixing until smooth. I stir in 2 cups flour, ½ tsp cinnamon, 1 tsp baking soda, and ¼ tsp salt until just combined, then fold in 3 cups quick oats. Using a 1–1.5 tbsp cookie scoop, I portion dough balls, spacing them 2 inches apart on the baking sheets. I bake for 9–11 minutes until set but soft, then cool on the sheets for 10 minutes before transferring to a wire rack.

In a clean bowl, I beat ¾ cup softened butter on medium until fluffy. I add 2 oz cream cheese and mix until smooth. Gradually, I mix in 3–4 cups powdered sugar, 1 tsp vanilla, and ¼ tsp salt, adjusting with 1 tbsp cream if needed for a spreadable consistency.

I spread 1–1.5 tbsp of filling on the bottom of one cooled cookie and top with another cookie, bottoms facing inward, to form a sandwich. I repeat with the remaining cookies.

I serve immediately or store for later, enjoying the chewy, creamy goodness.