Combine the raspberry vinegar with 2 cups of water in a large, non-reactive pot over medium-high heat.

Stir in the sugar, coarse salt, minced garlic, pink peppercorns, bay leaves, turmeric, and grated ginger.

Bring the mixture to a rolling boil.

Cook until the sugar completely dissolves, about 2 minutes.

Remove the pot from the heat and stir in the chopped fresh parsley.

Allow the brining liquid to cool completely to room temperature.

Use a mandoline or sharp knife to cut the yellow squash, zucchini, and red bell pepper into very thin, uniform slices.

If using shishito peppers, briefly blanch them in boiling water, then immediately transfer them to an ice water bath to lock in their vibrant green color.

Drain the blanched peppers well.

Layer the sliced vegetables and whole shishito peppers tightly into clean, heavy glass preserving jars.

Pour the cooled brining liquid into the jars, ensuring all the vegetables are completely submerged.

Seal the containers tightly.

Refrigerate for at least 4 hours to allow the flavors to develop, though they can be stored for up to several weeks.

Drain the pickles from the brine before serving, reserving the extra liquid for repacking leftovers.