Make cake: Preheat oven to 325°F. Butter a 9- by 5-inch loaf pan. Use a mixer to cream butter and sugar. Beat in almond extract, applesauce and sour cream.
Combine flour, baking powder and salt in a separate bowl. Reduce mixer speed; add flour mixture in 3 parts. Beat in yolks. In a separate bowl, beat egg whites until soft peaks form. Fold 1/3 of whites into batter. Gently fold in remaining whites. Pour into pan; bake until a toothpick inserted into center comes out clean, 1 hour and 10 minutes. Cool on rack for 10 minutes, then turn cake out. (Can be made 2 days ahead; wrap in foil and refrigerate.)
Make sauce: Mix cherries, sugar, lemon juice and preserves; simmer over mediumlow heat, stirring often, until warmed, about 7 minutes. Drain cherries and return juices to pan. Boil juices until reduced by half, 5 minutes. Return cherries to pan, remove from heat and stir in liquor; cool. (Can be made 2 days ahead; cover and chill.)
Assemble dessert: Slice cake. Use a heart-shaped cookie cutter to make 16 hearts. Toast Kir Royale Pour 2 teaspoons crème de cassis into each of 8 stem glasses and fill with chilled Champagne or sparkling white wine. Serve cold. Serves 8. PER SERVING: 103 Cal., 0g Fat, 0mg Chol., 0g Fiber, 0g Pro., 4g Carb., 6mg Sod. until lightly browned. Scoop ice cream onto serving plates. Arrange 2 hearts around scoops and add 2 Tbsp. sauce.