Preheat oven to 350 degrees F. Line a large rimmed baking sheet with nonstick foil. Set aside.
Cut bread into one inch cubes or smaller. Place into a large bowl. (If you don't have a bowl large enough for all of the bread, do half at a time).
Melt butter in the microwave. Whisk in olive oil and seasonings. Toss the butter mixture with the bread until everything is coated. **NOTE - if only doing half of the bread at a time, use only half of the butter each time.
Arrange the bread cubes in a single layer on a foil lined, rimmed baking sheet. Bake in the preheated 350 degree oven for 20-25 minutes, turning bread several times to ensure even browning. Allow to cool completely before eating.
If you don't have time to leave the bread out overnight, cut the cubes and toast them in the oven just for a minute, then toss in the butter and bake.
Store homemade croutons in a tightly sealed container or resealable storage bag and keep them in a cool spot in your pantry for about a week. They don't need refrigeration, but keeping them in the fridge could extend their life by at least a week, while losing only a little bit of crunch.
To freeze, place cooled croutons into a resealable freezer bag and freeze for up to 3 months. From the freezer, spread out on a baking sheet and bake at 250 for about 10 minutes to thaw and crisp them up.