Preheat the oven to 175°F (80°C).

Remove the crusts from the bread slices and cut them into 1-inch cubes.

Working in batches, pulse the bread cubes in a food processor until they are broken down into large, coarse flakes.

Spread the coarse bread flakes in a single layer on a baking sheet with parchment paper.

Bake for 15/ 20 minutes, until the flakes are lightly toasted and dried out. They should be dry and crispy but not browned.

Allow the homemade panko breadcrumbs to cool completely on the baking sheet before using or storing.