Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper.
In a mixing bowl, whisk together the flour, cocoa powder, baking soda, and salt.
In another bowl, beat the softened butter and sugar until fluffy and light in color.
Add the egg, vanilla extract, and red gel food coloring to the butter mixture, and mix until smooth.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Scoop tablespoon-sized balls of dough onto the prepared baking sheets, spacing them out evenly.
Use your thumb or the back of a spoon to create an indentation in the center of each dough ball.
Bake in the preheated oven for 12-15 minutes, or until the edges are set.
Let the cookies cool on the sheets for a few minutes before transferring them to a wire rack.
Once cooled, fill the indentations with cream cheese frosting.
