Preheat the oven to 350°F.
Gather the spinach in a clean dish towel and squeeze out all the moisture over the sink. You should have two golf balls of spinach. Set aside in a medium mixing bowl.
To the spinach, add the dairy-free cream cheese, sour cream, mayonnaise,
red pepper flakes, garlic, and salt. Stir until all the ingredients are fully incorporated. Pour the mixture into a small (6-inch) cast-iron skillet or ovenproof baking dish.
In a small mixing bowl, combine the panko or gluten-free breadcrumbs, parmesan (if using) and season lightly with salt. Sprinkle the topping over the dip in an even layer.
Bake for 20 minutes or until bubbling. If the top isn’t golden brown, raise the heat to 450°F and bake for another 5 minutes. Serve immediately alongside gluten-free crackers, tortilla chips or toast points. Though the gluten-free spinach dip is best warm, it is delicious at room temperature, too.