In a bowl, cream together 1 cup butter and the flour until smooth and creamy. Stir in heavy cream. Scrape dough into a ball.
Sprinkle the white sugar on a cutting board.
Roll out the dough to about a 1/4-inch thickness on the sugared surface. Using a 3-inch round cookie cutter, cut dough into 24 circles. Using the rolling pin, roll each circle into a slightly oval shape.
Place cookies on an ungreased cookie sheet about an inch apart.
Bake in the preheated oven until the edges of the cookies get very lightly brown, 10 to 12 minutes. Cool slightly on cookie sheet; then transfer them to cooling racks using a spatula.
To make the filling, mix together 1/2 cup of butter, confectioners' sugar, egg yolk, and Swedish arrack punsch in a bowl. Beat until mixture is well blended and creamy.
To assemble, spread about a rounded teaspoon of filling on the bottom of one cookie and place another cookie, bottom side down, on the filling to form a sandwich. Repeat with the rest of the cookies.
