Add the remaining 1/3 cup of water and whisk together. It will be nice and smooth and creamy. If not, add a little bit more water (this will depend on how creamy or thick your peanut butter is to begin with).
Add minced garlic and the teaspoon of sugar and whisk again.
Serve immediately with spring rolls or store in a fridge in a sealed container for about a week. (Makes about 1 cup and 2+ Tablespoons of peanut sauce.)
Just a little note about creamy peanut butters, some are thicker than others, towards the end, you might need to add a little more water to thin out the sauce a little bit. You will be able to tell by the thickness & creaminess of your peanut butter.