Lightly grease each 6 cm cup in a 12-cup muffin tin. For topping, melt butter in a small saucepan. Stir in sugar and Cinnamon until blended. Remove from heat and add half cup of the pineapple (save remainder for another use). Spoon about 1 tablespoon. of topping into each muffin cup. Place a cherry half, round side down, in center of each. In small bowl, combine flour, Baking Powder and salt. In another bowl, beat egg white with electric mixer until stiff peaks form. In large bowl, beat butter and sugar with electric mixer (no need to clean beaters) until fluffy. Beat in egg yolk and Vanilla Extract. Alternately add flour mixture and pineapple juice, beating well after each addition. Gently fold beaten egg white into batter. Pour evenly into muffin cups. Bake at 350� for 20 to 25 minutes or until cupcakes test done. Cool in pan on wire rack 10 minutes. Invert onto cookie sheet and gently tap each cup to release cupcakes. Serve warm or at room temperature.