Preheat your oven to 175°C (350°F).
Line a muffin tin with cupcake liners.
In a large mixing bowl, beat together the softened butter and white sugar until light and fluffy (about 2-3 minutes).
Add the large egg and yogurt to the butter mixture, mixing until well combined.
In a separate bowl, whisk together the flour, dark cocoa, salt, and baking soda. Gradually add this mixture to the wet ingredients, mixing just until combined.
Stir in the red food coloring and vanilla extract until the batter is evenly colored.
Fill each cupcake liner about two-thirds full with batter. Bake for 18-20 minutes, or until a toothpick comes out clean.
Allow the cupcakes to cool in the pan for about 5 minutes before transferring them to a wire rack to cool completely.
To make the frosting, beat the cream cheese and powdered sugar until smooth. Whip the cream until stiff peaks form, then fold it into the cream cheese mixture.
Once the cupcakes are completely cool, frost each one generously with the cream cheese frosting. Sprinkle with lime zest if desired.
