Butter, sugar, Coffee Syrup and crunchy bread = dangerous. Adapted from Cookpad Japan recipe.
Preheat the oven to 284°F
Slice bread into about 1/2" slices. Melt butter over medium heat, stirring frequently so as not to burn. Add sugar and cook until sugar is dissolved. Turn off heat and add Coffee Syrup. Stir well and let cool a bit to thicken.
Put sliced bread on a parchment paper lined baking pan. Spread a generous portion of the butter/syrup mixture on both sides of each slice. Sprinkle top with sanding sugar for garnish.
Bake for 50 minutes, rotating pan halfway through.
When the surface has dried, if it doesn't yield under the pressure of your finger, it's done.