Preheat oven to 325° F. Grease a deep 8-inch round cake pan, line bottom with paper and grease again. Pat maraschino cherries dry. Combine flour, ground almonds, baking powder and salt. Add cherries and toss until pieces are well coated; reserve. Beat butter, almond extract and sugar until light and fluffy. Beat in eggs one at a time, beating well after each addition. Stir in dry ingredient and zcherry mixture in 3 additions, alternately with sour cream. Spread into prepared pan. Bake 1-1/4 to 1-1/2 hours, or until toothpick inserted in centre comes out clean. Cool for 10 minutes. Turn cake out and cool completely. Serve with custard sauce.

To make custard sauce: Heat milk and cream, without boiling. Beat egg yolks with sugar; stir in milk gradually. In a saucepan, cook over medium heat without boiling until thickened, stirring constantly. Remove from heat. Stir in vanilla extract. Serve cold.