Preheat oven to 375 degrees and grease a 15x10x1-inch baking sheet.
In a large bowl, whisk together flour, sugar, baking powder, salt, and baking soda.
In a small saucepan combine the 1 cup of butter (cubed) and water. Bring just to a simmer. Stir into flour mixture.
In a small bowl, whisk together eggs, sour cream, and almond extract. Stir into flour mixture until mixed well.
Pour batter into prepared pan. Bake for 18 to 22 minutes or until a toothpick inserted in the center comes out clean. As soon as the cake comes out of the oven, make icing.
Combine butter and milk in a large saucepan. Bring just to a boil and remove from heat. Whisk in confectioner's sugar 1 cup at a time. Stir in almond extract and almonds. Spread over cake.