For the cookies:
1/2 cup unsalted butter, softened
1 1/2 cups sugar, divided
1 large egg
1 teaspoon vanilla extract
1 1/2 cups all-purpose flour
2 tablespoons natural unsweetened cocoa
1/2 teaspoon baking soda
1/4 teaspoon salt
Red gel food coloring
In a large bowl, beat butter and 1 cup sugar at medium speed with an electric mixer. Add egg and vanilla, beating until well blended.
In a separate bowl, combine flour, cocoa, baking soda, and salt.
Add flour mixture 1/2 cup at a time to butter mixture, beating well after each addition. Add desired amount of red gel food coloring, stirring well. Refrigerate for 1 hour.
Preheat oven to 350°. Line 2 baking sheets with parchment paper.
Using your hands, roll dough into 1 1/2-inch balls. Roll balls in remaining 1/2 cup sugar. Place 2 inches apart on prepared baking sheets; flatten slightly with a spatula.
Bake until slightly soft, 7 to 9 minutes. Let cool on baking sheets for 2 minutes. Transfer cookies to wire racks, and let cool completely. Spread cream cheese frosting on flat side of 1 cookie. Top with another cookie, flat side toward filling. Repeat with remaining cookies and filling.
Cream cheese frosting filling:
4 ounces cream cheese, softened
2 tablespoons unsalted butter, softened
2 cups confectioners’ sugar
1/2 teaspoon vanilla extract
In a large bowl, beat cream cheese and butter until creamy. Gradually add confectioners’ sugar, beating well after each addition. Add vanilla, beating well. (I put green gel coloring into half of the cream cheese frosting and left half white.)