Preheat oven to 375?F (191?C). Line baking sheets with parchment paper or silicone baking mats. Set aside.

In a large bowl, beat the butter, brown sugar, and granulated sugar together on medium-high speed until light and creamy, about 3 minutes. Add the egg, vanilla, and molasses and beat on high speed until combined, about 1 minute. Scrape down the sides and bottom of the bowl as needed.

In a medium bowl, whisk the flour, baking soda, salt, cinnamon, cloves, and oats.

With the mixer running on low speed, slowly add the dry ingredients to the wet ingredients. The dough will be thick and sticky; you may need to mix it by hand.

Scoop about 2 heaping Tablespoons of dough per cookie (45g each) and arrange 3 inches apart on the baking sheets.

Bake for 10?13 minutes or until the cookies are very lightly golden around the edges. The centers will look very soft.

Remove from the oven and cool the cookies on the baking sheet for 10 minutes before transferring to a cooling rack to cool completely.

For the filling: In a large bowl, beat the butter on high speed until creamy, about 1 minute. Add the confectioners? sugar and beat on medium speed for 1?2 minutes. Pour in the heavy cream and vanilla extract. Beat on high speed for 2?3 minutes. Add salt to taste, if needed.

Spread about 1.5 Tablespoons of cream filling on the bottom side of half of the cookies; top with remaining cookies, right side up.

Cover and store leftover sandwich cookies at room temperature for up to 2 days, or in the refrigerator for up to 5 days.