Heat oven to 350°F. Line a jelly-roll pan with waxed paper. Lightly coat paper with nonstick vegetable-oil cooking spray.
Combine flour, baking powder, baking soda and salt in a bowl.
Beat together butter and sugar in second medium-size bowl until light and creamy. Add egg whites and coconut extract; beat until fluffy. On low speed, alternately beat in flour mixture and buttermilk in 3 additions. Fold in coconut. Spread evenly in prepared pan.
Bake in 350°F oven for 25 minutes or until cake springs back in center when lightly pressed with finger. Cool cake in pan on rack 10 minutes. Remove cake from pan to rack to cool completely. Trim 1 inch from short ends of cake. Cut crosswise into thirds.
Combine jelly and cherries in saucepan. Bring to simmering; cook 8 minutes. Place in blender. Whirl until smooth. Transfer to bowl; cool.
Spread half of filling over one layer. Top with another layer and spread with remaining filling. Top with third layer.
Beat together the heavy cream and sugar in medium-size bowl until thickened. Spoon the cream into a pastry bag fitted with large star tip. Pipe the cream decoratively over top of cake.
Place cake in refrigerator overnight to firm up cake for easier slicing. Sprinkle the shredded coconut over the top of the cake. Garnish with raspberries and cherries if you wish.