• Combine 6 egg yolks and 1 cup of the sugar in a medium saucepan. Add 4 oz lime juice, Zest from all the limes and ⅛ teaspoon salt.
• Put 3 oz of the butter into a bowl, place a fine mesh sieve over the bowl and keep it near the stove.
• Heat the yolk mixture over medium low heat, stirring constantly. You must be sure to keep stirring across the entire bottom and corners of the pot so the custard does not have a chance to stick. The mixture will start out opaque with a fine white foam over the surface. As it heats up the curd will thicken, become more translucent and the foam will disappear. Cook until the curd will coat the back of a wooden spoon or silcone spatula. Don't allow it to come to a full boil.
• Immediately remove from the heat and pour through the sieve over the butter in the bowl. Stir until the butter melts. Cover and refrigerate until completely chilled, at least an hour.

Prepare the Ramekins

• Melt the remaining 1 ounce of butter. Brush the insides of six 8-ounce ramekins with melted butter.
• Cut 6 pieces of parchment, each 12" long by 4" wide. Butter one side of a strip of parchment. With the buttered side facing in, wrap the top of a ramekin with the parchment to form a collar that extends at least 2" over the top of the ramekin. Tape the parchment to hold it in place. Repeat with the remaining parchment strips. Put the ramekin on a tray.
• Scoop a tablespoon of graham cracker crumbs into each ramekin. Roll the crumbs around to coat the inside of the ramekins and collars. Dump excess crumbs into a small bowl and set aside for later.
• Remove the chilled lime curd from the refrigerator. Whip 8 oz heavy cream to full peak and fold into the lime curd.
• In a clean bowl, whip 6 egg whites to soft peak. Slowly add the remaining 1/2 cup of sugar and whip to full peak. Fold the egg whites into the lime mixture in 3 batches.
• Divide the souffle mix among prepared ramekins. I find an ice cream scoop works well for portioning the batter. The batter will be higher than the top of the ramekin, but the paper collar will hold it in place. Use a small spatula to level off the souffles. Place the tray of the souffles in the freezer for at least 3-4 hours until frozen. (See note)
• To serve the souffles, remove the collar and top with a sprinkle of graham cracker crumbs, a rosette of whipped cream and a sprinkle of grated lime zest.