Tear the bread into medium sized chunks and add them to a food processor.
Blitz for a couple of minutes until they have a coarse, soft powder-like consistency.
Arrange them on a lined baking sheet in a single layer.
Pop them in your oven preheated at 300°F for about 10 minutes.
Transfer them to a glass bowl and allow them to cool down completely.
Use immediately or store for later.
Notes
I kept these breadcrumbs lightly toasted, which is why they don't have that light golden brown color. If you prefer the breadcrumbs toasty, let them stay in the oven for a few extra minutes, but keep an eye on them so they don't end up burning.
Another good trick is to drizzle some olive oil over them once you layer them on the baking sheet. This will help them crisp up nicely and turn golden brown. I love using my rosemary and garlic infused oil here.
I processed the bread first and then oven-dried it to make the breadcrumbs. If you want, you can do it the other way round and first toast the bread chunks in the oven and then blitz them in the food processor.
Sometimes, when I want really fine crumbs, I like to process them again after I bake them, and even pass them through a mesh sieve to remove all the larger chunks.
If your breadcrumbs seem to have lost their crunch after a couple of weeks of storage, layer them on a baking sheet and bake once again at a low temperature for a few minutes to dry them up!