This sandwich is one of my absolute favorites during the fall. Crisp tart apples combined with warm flavors like cinnamon and honey is the best combination!
In a small bowl with a whisk, or in a mini food processor, whip the mascarpone and honey together until well combined and fluffy.
Heat the panini press to medium-high heat.
For each sandwich: spread butter on two slices of bread, flip over and spread 1 tablespoon of the mascarpone mixture on each slice, top one slice of bread with apple slices, and close the sandwich with the other piece of bread, buttered side up.
Sprinkle brown sugar on top.
Grill two panini at a time, with the lid closed, until the filling is warm and the bread is toasted, with a sweet crust, about 3-5 minutes.