How to Make It
Combine raspberries, powdered sugar, and 2 tablespoons lemon juice in a blender; process until smooth. Strain raspberry mixture through a fine wire-mesh sieve, discarding solids.
Preheat oven to 325°. Coat the insides of 10 (8-ounce) ramekins with butter; sprinkle 1/4 cup granulated sugar evenly among ramekins, tilting to coat and tapping to remove excess. Set aside.
Beat egg yolks in a medium mixing bowl at medium speed with an electric mixer about 4 minutes or until thick. Gradually add 1 cup granulated sugar, beating constantly until well combined. Stir in lemon zest and remaining 3 tablespoons lemon juice.
Beat egg whites in a large mixing bowl at high speed with an electric mixer until soft peaks form. Gradually add remaining 1/4 cup granulated sugar, beating constantly until stiff peaks form. (Do not overbeat.) Gently fold one-fourth of egg whites into yolk mixture; gently fold in remaining egg white mixture. Gently spoon mixture into prepared dishes. Arrange dishes in a large roasting pan; add hot water to roasting pan to a depth of 1 inch.
Bake 30 minutes or until a wooden pick inserted into the side of the soufflés comes out clean. Serve soufflés immediately with raspberry sauce.