Chocolate Fudge Sauce for swirls/mix-in/topping

Chocolate fudge sauce from Polar Ice Creamery - I do not take credit. Halve the recipe to reduce waste if there is no plan for the leftover fudge.

Ingredients:

40g brown sugar
70g white sugar
25g Dutch process cocoa powder or regular cocoa powder
57g or 4 TBSP butter
62 g or 60 mL milk or cream
30 g or 1.5 TBSP corn syrup/golden syrup
2.5 g or 1/2 teaspoon vanilla extract

Instructions:

1. Put milk, sugars, and butter into a pot and heat to melt.
2. Add in cocoa powder and stir well. Reach a vigorous boil and turn off the heat.
3. Allow to cool and then add in vanilla extract. Cool further and store in container in the fridge.