1. Preheat oven to 350 degrees.

2. In a large skillet, combine pears, 1/3 cup sugar, salt, and lemon juice and cook over medium-high heat, stirring occasionally, until pears are soft and juicy, about 10 minutes. Increase heat to high and continue cooking until liquid evaporates, about 5 minutes. Remove from heat; let cool to room temperature.

3. In a medium bowl, combine butter, remaining tablespoon sugar, and cinnamon; mix until smooth.

4. Lay the side of a 5-ounce ramekin on top of the bread, and cut bread into pieces that are 1/2 inch thicker than the height of the ramekin. Turn each piece on its side and slice 3/8 inch thick.

5. Butter one side of each piece of brioche with the cinnamon-sugar butter. With a long side of the bread closest to you, cut each slice vertically into 4 equal pieces. Line only the sides of the ramekins with the brioche pieces, buttered side against the ramekins. Bread should fit snugly around ramekins without any gaps.

6. Divide pear mixture evenly between each ramekin, pressing down to compact. Using a serrated knife, trim off any bread that extends above the rim of the ramekins.

7. Place ramekins on a baking sheet. Bake until tops are golden brown, about 20 minutes. Remove from oven and let cool 5 minutes, and then invert onto individual plates to unmold. Drizzle custard sauce around each charlotte and top with chantilly cream. Serve warm.