Prepare the Cookie Dough: In a bowl beat butter until light and fluffy, about 2 to 3 minutes, scraping the bowl periodically. With the mixer on low, slowly add the flour followed by the cream, mixing until it forms a dough. Cover the dough with plastic wrap and refrigerate for a minimum of 2 hours.
Prepare for Baking: Preheat oven to 375°F and line two baking sheets with parchment paper, set aside. Prepare the granulated sugar in a bowl for coating the cookies.
Shape the Cookies: On a lightly floured surface, roll out the dough to 1/8th-inch thickness. Use a cookie cutter or a small round cup rim to cut out the cookies. Press the tops of the cookies into the sugar and then place onto the prepared baking sheet. Using a fork, prick the tops of the cookies to create a decorative pattern and prevent them from puffing up too much.
Bake the Cookies: Bake for 7 to 9 minutes, removing from the oven before the cookies start to brown. The cookies should remain pale for the authentic cream wafer look. Cool completely on a wire rack before filling.
Make the Frosting: In a bowl beat butter and salt until smooth, fluffy, and lump free about 3 to 5 minutes. Gradually add in powdered sugar followed by the vanilla. Slowly add the heavy cream a tablespoon at a time until it reaches a thick but spreadable consistency. Divide the frosting in half and color it with food dye, if desired.
Assemble the Cookies: Spread frosting onto the bottom side of one cookie and sandwich another cookie bottom on top of it. Repeat with the remaining cookies until all are paired into delightful sandwich cookies.