I love making breadcrumbs with any leftover bread I have - especially those end pieces you usually just throw out. You can mix any type of bread together and it stores really nicely in the freezer.
I typically buy a few different types of bread at any given point depending on what I am cooking that week. Unused slices usually end up in the freezer. I had a vacation day today and after grocery shopping and organizing my freezer I took some frozen slices out and started toasting!
Pre-heat your oven to 350 F and toast the frozen slices for 10 minutes. Flip the slices over and continue to cook for another 5 minutes. Keep an eye on them to make sure they are not burning but you do want them pretty crispy so you don't get soggy breadcrumbs. If you need to, continue toasting after the 15 minute mark - It all really depends on your oven and what type of bread you are using at the time.
Once the bread is finished toasting remove from the oven and let cool completely. Making sure the bread cools all the way will also help avoid soggy breadcrumbs.
When ready, tear the bread up into smaller pieces and place in a food processor.
**At this point you could throw in toasted nuts, seeds, or oats for more texture and flavor**
Pulse on high until the bread has been broken down into small crumbs. The finer you like your crumb the longer you will need to pulse.
And that's all there is too it. Put the crumbs in a freezer safe ziplock bag or container (and if your an organizational freak like I am label with what it is and the date) an freeze until needed!