Mix the brown sugar, melted butter, vanilla extract, and salt in a small bowl until well incorporated.
Lay the peaches skin side up in a grill pan.
Grill over direct, medium heat until they begin to soften; approximately 6 to 10 minutes depending on the size of the peach’ giving the grill lid open
Flip the peaches, so the skin side is now down, and sprinkle the brown sugar mixture over each peach.
Continue grilling for an additional 6 to 10 minutes, until the juice begins to bubble around the edges of the skin; signaling that the peaches are done.
Place the peaches in serving bowls and top with a scoop of vanilla ice cream