Preheat oven to 375 degrees and spray a 15x10-inch pan with baking spray with flour.
Place 1/2 cup butter in a large microwave-safe bowl and microwave until melted.
Add sugar, water, vegetable oil, buttermilk, eggs, orange zest, orange extract and almond extract to the bowl. Use a hand-held electric mixer to beat at medium-speed until combined.
Sift the flour, baking soda and salt into the mixing bowl. Beat at low speed until combined. Transfer batter to prepared baking dish.
Bake for 20 to 22 minutes, or until a toothpick inserted in the center comes out clean. Let cool before frosting.
To make icing, place butter and milk in a large microwave-safe bowl and microwave until the butter is melted.Add the confectioners' sugar, salt, and almond extract to the bowl, and beat until smooth. Pour icing over cooled cake. Sprinkle with almonds.