Prepare syrup: In small saucepan, combine honey, water and rosemary. Heat over medium heat 5-10 minutes or until just bubbling. Reduce heat; simmer 5 minutes. Syrup will be thin. Set aside.
Prepare sandwich: Heat grill or grill pan until moderately hot. Coat with canola oil. Place peach halves, cut-side- down, in pan. Grill 5-7 minutes. Flip and grill another 3 minutes. Remove from grill and slice thin. Divide slices into 4 equal portions.
Butter 1 side of each brioche slice with 1 teaspoon butter. Smear 1-2 tablespoons Wisconsin marscapone cheese on reverse side of bread slices. Top 4 mascarpone-covered bread sides with 1 portion peach slices. Top with 4 remaining bread slices, butter-side-up.
Grill over medium heat 2-3 minutes per side. Remove from heat, open and drizzle with rosemary honey syrup.
For Rosemary Honey Syrup:
- 1/4 cup honey
- 1 tablespoon water
- 1 sprig rosemary
- 2 tablespoons canola oil
- 2 firm, ripe peaches, halved, pits removed
- 8 slices brioche bread
- 8 teaspoons butter
- 1 cup (8 ounces) Wisconsin Mascarpone cheese