Preheat the oven to 350°F and line a large baking sheet with parchment paper.
In a small saucepan, gently heat the olive oil and smashed garlic until aromatic, about 1 minute. Remove from the heat.
Cut the bread into cubes and place them on the baking sheet. Remove the garlic from the saucepan and drizzle the garlic oil over the bread. Sprinkle with sea salt, toss to coat, and spread the bread in a single layer on the baking sheet. Bake for 10 to 18 minutes or until golden brown and crisp. The timing will depend on your bread and how crispy you like your croutons. Sprinkle with dried parsley.
For grilled croutons: Drizzle whole bread slices with olive oil and grill until lightly charred. Use the cut-side of a halved piece of garlic to rub garlic onto the hot bread. Slice the grilled bread into cubes.