Rich & Fudgy Guinness Brownies (Easy St. Patrick’s Day Dessert)

These rich and fudgy Guinness brownies are the kind of easy dessert that feels special without keeping you in the kitchen all day. A dark chocolate brownie mix gives you a dependable start, while Guinness stout deepens the chocolate flavor and makes every bite taste a little more grown up.

They are perfect for St. Patrick’s Day, but there is no reason to wait for March. Make them for a casual supper, a game-day gathering, or any afternoon when you are craving a warm, deeply chocolate dessert.

Why You’ll Love These Guinness Brownies

• A boxed brownie mix keeps the recipe quick and reliable.
• Guinness adds depth without giving the brownies a strong beer flavor.
• The soft fudge icing makes the brownies feel homemade and extra special.
• The batter comes together in one bowl with simple ingredients.
• They can be made ahead and freeze beautifully.

What You’ll Need

Choose a dark chocolate or chocolate fudge brownie mix for the richest flavor. Eggs, oil, vanilla, and Guinness turn it into a tender brownie batter. Semisweet chocolate morsels are optional, but they add little pockets of melted chocolate throughout.

For the icing, you will need semisweet chocolate chips, salted butter, Guinness, sifted powdered sugar, and a little vanilla. Sifting the sugar helps the finished icing stay glossy and smooth.

How to Make the Brownies

1. Preheat the oven to 350°F and prepare an 8 by 8-inch or 9 by 9-inch baking pan. Parchment paper makes it easy to lift the cooled brownies from the pan.
2. Combine the brownie mix, slightly beaten eggs, Guinness, vegetable oil, and vanilla in a large bowl.
3. Stir gently just until the dry mix disappears. Fold in the chocolate morsels if you are using them.
4. Spread the batter evenly in the prepared pan and bake for 20 to 25 minutes.
5. Check the brownies by inserting a toothpick about 1 inch from the edge. It should come out clean while the center remains soft and fudgy.
6. Let the brownies cool completely before cutting or adding the icing.

How to Make Guinness Fudge Icing

This icing is soft, glossy, and fudgy rather than firm like a traditional frosting. It comes together quickly on the stovetop and settles into a smooth chocolate layer as it cools.

1. Combine the chocolate chips, butter, and Guinness in a small saucepan.
2. Warm the mixture over low heat and stir until completely melted and smooth.
3. Remove it from the heat, then whisk in the sifted powdered sugar and vanilla.
4. Spread the warm icing over the cooled brownies and let it set before serving.

Successful Tips

• Do not overmix the batter. Stir only until the ingredients are combined.
• Check near the edge rather than the center when testing for doneness. This keeps the middle fudgy.
• Let the brownies cool before icing so the topping stays in a neat layer.
• If the icing becomes too thick, whisk in 1 teaspoon of warm Guinness or milk at a time.
• For an alcohol-free version, replace the Guinness in both the brownies and icing with milk or water.

Storage and Freezing

Store the brownies in an airtight container at room temperature for up to 4 days. For longer storage, wrap the brownies well and freeze them for up to 2 months. Thaw overnight in the refrigerator, then bring them to room temperature or warm them gently before serving.