Preheat the oven to 350°F Coat a 12-cup Bundt pan with cooking spray, then dust with flour.
To prepare the cake: Toast the almonds in a large deep skillet over medium heat, stirring often, for about 3 minutes or until lightly golden. Tip into a bowl and set 1/2 cup aside.
Combine 1 1/2 cups of the almonds and 1/2 cup of the sugar in a food processor fitted with a metal blade. Process until the almonds are finely ground. Combine the ground almonds, flour, baking powder, baking soda, salt, and remaining 1 cup sugar in a large bowl. Add the buttermilk, eggs, egg whites, oil, lemon juice, and almond extract. Whisk until well combined. Fold in the blueberries, raspberries, and cherries. Pour the batter into the prepared pan.
Bake in the center of the oven for 65 to 70 minutes or until a wooden toothpick inserted into the cake comes out clean. Place pan on a rack and let cool for 15 minutes. Remove the cake from the pan, transfer to the rack, and let cool completely.
To prepare the glaze: Combine the confectioners' sugar and buttermilk in a bowl and stir until dissolved. Spoon over the cake. Coarsely chop the reserved 1/2 cup almonds and sprinkle over the top of the cake onto the glaze. Let set at least 15 minutes before serving.