14ouncessweetened condensed milkcold (chilled for at least 2 hours or overnight)
¼cupchocolate curlsfor garnish
Preheat oven to 350 degrees F. Line a 3 inch deep 8x8 square baking pan with parchment paper. Leave an additional 2 inches of parchment paper for overhang on each side of the pan. Spray with nonstick baking spray.
In a small microwave-safe bowl, add the chopped unsweetened chocolate and microwave in 20-second increments until melted. Stirring after each increment to avoid burning.
In a large bowl, add the eggs. Beat with a hand mixer on medium until frothy.
Add in the sugar, walnuts, orange juice concentrate, and zest to the eggs. Don’t stir.
Pour the slightly cooled chocolate mixture over the top and beat with mixer until combined.
Add the flour and mix well.
Pour the batter into the prepared pan.
Place in the preheated oven and bake for 40-45 minutes or until the sides start to pull away.
Remove from the oven and allow to cool to room temperature.
In large bowl, add the butter and bear with a hand mixer until light and fluffy.
Pour in the can of sweetened condensed milk and orange extract. Beat on medium until thoroughly mixed and thickened.
Spread the frosting over the brownies and garnish with chocolate curls and/or orange zest if desired.
Cut into bars for serving. Refrigerate until served or any leftovers.