In a large bowl, whisk together flour, cinnamon, ginger, baking soda, cloves, salt, and nutmeg.
In a separate bowl add eggs, molasses, and vanilla.
Using a stand mixer with a paddle attachment or by hand, beat butter and sugar for 2 minutes on medium-high until light and fluffy.
Reduce mixer speed to low and slowly add in the dry ingredient mixture until just combined.
Divide dough into two equal parts, shape into balls, then flatten each into a 1-inch thick disk and wrap tightly in plastic wrap.Chill dough disks in the refrigerator for 1 hours or overnight.
Baking Cookies
Prepare a baking sheet with parchment paper or a silicone liner, and preheat the oven to 350°F.
Roll out dough on a lightly floured surface to ⅛ inch thick, cut shapes with cookie cutters, and transfer to baking sheets.
To create heart-shaped centers, use a Heart Fondant Plunger Cutter, ensuring an even number of cookies with and without heart cutouts.Chill cookie cutouts on baking sheet in the fridge for 5-10 minutes before baking to maintain their shape.
Bake for 8-10 minutes, then cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Eggnog buttercream
Gather all frosting ingredients and set up your stand mixer with a whisk attachment.
Beat butter in the mixer’s bowl until light and creamy, about 5 minutes.
Gradually add powdered sugar, mixing well after each addition until fully incorporated.
Mix in nutmeg, eggnog, vanilla extract, and salt; beat on high for 8-10 minutes until smooth.
Fill a piping bag with the buttercream and twist the open end to seal.
Gingerbread cookie sandwiches assembly
Place solid gingerbread cookies upside down; these will be the base for the buttercream.
Pipe eggnog buttercream onto the base cookies.
Gently place cookies with cutout hearts on top of the buttercream to form sandwiches.
Enjoy your gingerbread cookie sandwiches as a delightful treat, and consider gifting them to friends and family for a homemade holiday surprise!