Prepare the Easy Hot Fudge Sauce according to the instructions, whisk in 2 tablespoons of cocoa powder, and pour it into a jar to cool. Refrigerate for at least 4 hours until completely set and firm.

Combine butter and both sugars in a large bowl and cream together until pale and fluffy. Mix in the egg and vanilla extract until well combined.

Sift flour, cocoa powder, baking soda, and salt into a medium bowl and whisk to blend evenly. Add the flour mixture to the butter mixture and fold in until just incorporated. Cover the bowl and refrigerate the dough for 2 hours.

Scoop teaspoons of chilled fudge sauce, roll them in cocoa powder to coat, and place on a parchment-lined plate or tray. Freeze for 30 minutes until firm.

Use a 1 ½-oz cookie scoop to portion dough and roll into 14 balls. Flatten each ball into a disk about 2 ½ inches in diameter. Place a fudge ball in the center and wrap the dough around it, ensuring no gaps. Repeat with remaining dough balls and refrigerate again for 15 minutes.

Preheat oven to 375°F and line two large cookie sheets with parchment paper.

Place the chilled dough balls on the lined trays, spacing them 3 inches apart, and bake for 8-10 minutes until set around the edges and slightly soft in the middle. Let cookies cool completely on the baking sheet.