Lightly coat a 2 1/2-quart oven-safe bowl with cooking spray; line with plastic wrap. Lightly coat the surface of wrap with cooking spray. Set aside.
Spoon applesauce onto several layers of paper towels; spread to 1/2-inch thickness. Cover with additional paper towels; let stand 5 minutes. Scrape into a small bowl using a rubber spatula.
Beat 3 tablespoons butter at medium speed with an electric mixer 2 minutes or until fluffy. Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, baking soda, and salt. Add flour mixture, 1 1/4 cups milk, and molasses to the butter, beating until blended. Stir in applesauce and raisins. Spoon mixture into prepared bowl; cover bowl with plastic wrap.
Place bowl in a deep roasting pan. Add hot water to pan until water is one-third way up the sides of bowl. Tightly cover bowl and pan with aluminum foil. Bake at 350° for 2 hours or until a wooden pick inserted in center comes out clean. Remove bowl from roasting pan. Carefully invert bowl onto a serving plate; remove bowl. Remove and discard plastic wrap.
To prepare sauce, combine 3/4 cup sugar and next 6 ingredients (through salt) in a medium saucepan over medium heat, stirring constantly with a whisk until smooth. Cook, stirring frequently, 4 minutes or until thickened. Remove from heat. Stir in rind and vanilla. Let stand at least 5 minutes before serving.