Heat oven to 350°F.

Spray 13 x 9-inch pan with cooking spray.

In large bowl, beat 1 cup butter with electric mixer on medium speed until smooth and creamy.

Beat in granulated and brown sugars, 1 teaspoon vanilla and the eggs until smooth.

On low speed, beat in flour, ¾ cup cocoa, the salt and baking soda until soft dough forms.

Stir in chocolate chips, marshmallows and cashews.

Spread in pan.

Bake 15 to 20 minutes or until set.

Cool completely, about 1 hour.

In small bowl, mix all frosting ingredients except cocoa and cashews, adding enough of the half-and-half until frosting is smooth and spreadable.

Spread over brownies.

Sprinkle with ¼ teaspoon cocoa and additional cashews.

Let stand about 30 minutes or until frosting is set.

Cut into 6 rows by 4 rows