Preheat oven to 400 degrees F. Arrange workspace, placing flour, egg, and panko in separate bowls. Mix salt and pepper into panko.
Cut cauliflower into bite-sized florets. Working in batches, coat the florets in flour, then egg, then breadcrumbs. Set on a parchment paper-lined baking sheet. Bake for 15 to 20 minutes, or until crispy.
Set a small saucepan over medium heat and add all “Sauce” ingredients. Whisk to combine and bring to a simmer and cook for about 5 minutes, until it begins to thicken.
Drizzle sauce over the baked cauliflower and gently toss to evenly coat.