1. Preheat oven to 350 f. Lay your walnuts out in a single layer on a rimmed baking sheet.
2. Add ravioli to a large pot of boiling water, and cook according to instructions. The walnuts take 5-10 minutes to toast, so put them into the preheated oven so that they'll be done at about the same time as your pasta.
3. In a large skillet, melt the butter on medium heat, and allow to simmer a bit until slightly browned. Once butter is brown, whisk in the balsamic vinegar, and turn down the heat to keep the sauce warm.
4. Drain your pasta, and throw it all into the pan with the sauce. toss it around to evenly coat it, making sure not to break it apart. When walnuts are ready (you'll know because you'll start to smell them, and they'll be a nice golden brown), take them out of the oven and use them to top each portion of pasta. You may want to roughly chop them once they're done, but make sure you don't chop them BEFORE toasting them.
Top with vegan parmesan if desired. This dish is great with a side of roasted asparagus, and a nice glass of wine!