Preheat your oven to 300°F. Slice the bread thinly and arrange the slices in a single layer on a baking sheet.
Toast the bread for 5 minutes, then flip the slices and toast for another 5 minutes until the bread is dry but not browned. Remove from the oven and let cool on a wire rack.
Break the toasted bread into pieces and place them in a food processor. Pulse in batches until you achieve fine crumbs. For a finer texture, add some of the chopped parsley in the final batch and pulse briefly for about 20-30 seconds.
In a large bowl, combine all the bread crumbs with the remaining parsley, dried oregano, dried thyme, dried rosemary, onion powder, garlic powder, salt, and black pepper.
Place the finished bread crumbs in an airtight container. They will keep in the refrigerator for up to two weeks or in the freezer for up to three months.