Place 3 Tbsp. Hellmann's® in a small bowl; set aside. Place bread slices on a cutting board. Evenly spread all slices with remaining mayonnaise. Evenly top 4 of the bread slices with ham slices.
Cut the rind off the Brie. Divide the cheese into 4 equal parts, then cut each part into thick slices. Place Brie slices evenly on top of ham slices. Top with remaining bread, mayonnaise side down, to close each sandwich.
Spread reserved Mayonnaise in a thin layer on the outer top and bottom bread slices of each sandwich. Place in a large nonstick skillet and cook over medium-high heat, pressing gently, and turning once, until both sides of bread are golden brown and Brie is melted, working in batches if necessary. Serve hot and enjoy!