Thoroughly butter a small baking dish and set aside.
Place sugar, cornstarch, corn syrup, butter, water, and salt in a medium-sized saucepan on medium-high heat.
Heat until the mixture reaches 255 F on a candy thermometer and immediately remove from the heat. Note: If you read other salt water taffy recipes, you'll see a range of temperatures. The higher the temperature, the harder the taffy will be. 255 F makes a candy that holds its shape but dissolves in your mouth.
Mix vanilla bean paste into the hot taffy.
Pour the hot taffy into the buttered baking dish.
Cover taffy with a layer of nonpareils.
When the taffy is cool enough to handle, butter your hands, form a big taffy ball, and begin to stretch and pull. Imagine you are a kid with bubble gum in your mouth, pulling a piece of it way out, rejoining it to the ball, and then pulling again (but, if you can resist, don't put any in your mouth yet - the taffy will be much better after the pull). Keep doing this for about 15 minutes. Pulling the taffy aerates it, which makes it softer and more chewy. As you pull, you'll notice that the color of the taffy becomes significantly lighter. You'll also notice that the taffy will get much tougher to pull. When your arms get really tired and it starts to feel like you are using one of those exercise stretch bands, you're done. Don't stress about doing it right. Just have fun! Look at the color of the taffy at the very beginning of the pull. You'll see that it gets much lighter as the process continues.
Do one last pull to make the taffy into a long rope with the thickness that you'd like your final product to be.
Butter a pair of scissors (be careful not to cut yourself).
Cut the taffy into bite-sized pieces.
Cut wax paper into small squares.
Wrap taffy in the wax squares.