These Frosted Lemon Brownies have a rich, chewy base (giving them their brownie status) topped with lemon ermine frosting for an extra burst of citrusy flavor! If you love the citrusy zing (and there is plenty of it, which I love) of these Frosted Lemon Brownies, why not try a spiced twist on the classic brownie with my popular Gingerbread Brownies? And, of course, I’ve got the classic homemade brownie mix recipe that’s always a hit when you just want to keep things simple!
Ingredients & Substitutions
- Butter: I used 2 sticks of unsalted butter in these lemon brownies with another 2 sticks for the ermine (for a total of 4 sticks of butter). The butter in the brownies helps give them a soft, chewy texture and adds a delicious buttery flavor! If using salted butter, you may want to lessen the amount of salt in the recipe.
- Brown Sugar: Light brown sugar is used in these lemon brownies because it adds a little extra flavor and moisture. The molasses in the brown sugar makes the brownies taste a bit richer and helps keep them soft. It also helps the brownies get a nice golden color.
- Lemon Flavor: For the bright lemon flavor in the lemon brownies, I added freshly squeezed lemon juice and lemon zest. Bottled juice can work in a pinch, but for the most authentic lemon flavor, freshly squeezed is best. Zest the lemon before juicing it.
- Cornstarch: The cornstarch helps make the lemon brownies extra soft and chewy. It helps give the texture a little more thickness, so the brownies aren’t too cake-like or too dense. It also helps them hold together better when you cut them into squares
- Lemon Ermine Frosting: I really wanted the lemon flavor to pop, so I added my lemon ermine frosting (with slightly less amount of lemon juice) on top. Ermine Frosting is a frosting usually made with a cooked mixture of milk and flour. (I also have chocolate ermine and strawberry ermine frosting.) But, in this recipe, instead of milk, I cooked freshly squeezed lemon juice with the flour for the bright lemon flavor.
Can I Make The Frosting Ahead Of Time?
Yes! You can make lemon ermine frosting ahead of time. Store it in an airtight container in the refrigerator for up to a week. When ready to use it, let it sit at room temperature for about 15-20 minutes, then re-whip it with a mixer to bring back its light and fluffy texture. If it’s too thick, you can add a splash of milk while whipping.
Can I Use A Different Frosting For Lemon Brownies?
Yes, if you want to try a different frosting, or if ermine is not your thing, there are other delicious options you can try!
- Whipped Lemon Buttercream (from my Lemon Cake and Easy Lemon Cupcakes)
- Whipped Cream Cheese Frosting
- Cream Cheese Frosting (from my homemade carrot cake recipe)
- A simple glaze
Lemon Brownies vs. Lemon Bars: Key Differences
What is the difference between lemon brownies and lemon bars? Lemon brownies don’t have a crust and have that dense, fudgy texture you love in a classic brownie. Plus, they come with a delicious frosting or glaze on top (totally optional, but highly recommended!). Lemon bars, though, have a buttery crust with a zesty lemon filling. If you’re a fan of lemony treats, you’ve got to try both—each one is a winner!
How To Store Frosted Lemon Brownies
To store lemon brownies with lemon ermine frosting, keep them in an airtight container in the refrigerator. They should stay fresh for up to 3-4 days.
Can You Freeze Lemon Brownies?
Yes, you can freeze the brownies, but I recommend freezing them before adding the frosting. To freeze lemon brownies:
- Bake and Cool: Bake the brownies and let them cool completely.
- Freeze: Once cooled, wrap them tightly in plastic wrap and then in aluminum foil or place them in an airtight container. Freeze for up to 3 months.
- Thaw: When ready to frost, let the brownies thaw at room temperature for about 2-3 hours before adding the lemon ermine frosting.
Frosted Lemon Brownies
Ingredients
Lemon Brownies
- 1 cup (2 sticks / 227 g) unsalted butter, melted
- 1 ¾ cups (350 g) light brown sugar, packed
- 3 large eggs, room temperature
- ¼ cup (61 g) lemon juice, about 2 medium lemons
- 1 teaspoon lemon zest
- 2 ½ cups (312.5 g) all-purpose flour
- 2 teaspoons cornstarch
- 1 teaspoon baking powder
- ½ teaspoon kosher salt
Lemon Frosting
- ¾ cup freshly squeezed lemon juice, 4-5 medium lemons
- 5 tablespoons all-purpose flour
- 1 cup (2 sticks / 227 g) unsalted butter, room temperature
- 1 cup (200 g) granulated sugar
Instructions
- Preheat oven to 350°F. Line a 9×9-inch baking dish with parchment paper.
- In a large bowl, combine the melted butter and brown sugar. Stir well.
- Add the eggs one at a time, stirring well after each addition.
- Stir in the lemon juice and lemon zest.
- In a separate, medium-sized bowl, whisk together the flour, cornstarch, baking powder, and salt.
- Gradually stir the flour mixture into the butter and egg mixture until completely combined.
- Spread the batter evenly into the prepared pan. Bake for 30-35 minutes, or until the edges are turning slightly golden brown. (You don't want to overbake these brownies!)
- Allow brownies to cool completely before frosting.
Lemon Frosting
- While the brownies are cooling, make the lemon frosting. In a medium saucepan over medium heat, whisk together the lemon juice and flour. Cook, whisking constantly, for 1-2 minutes, or until boiling. Boil for one minute, still whisking constantly. Remove from heat and bring to room temperature.
- In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar on medium speed until light and fluffy (2-3 minutes). Stop the mixer and use a rubber spatula to scrape down the sides of the bowl.
- Add the room-temperature lemon mixture to the bowl of the stand mixer. Beat on medium-high speed until the frosting is light and fluffy (2-3 minutes), pausing to scrape down the sides of the bowl as needed.
- Switch to the whisk attachment. Mix on high for 7-8 minutes, or until the frosting is smooth and creamy.
- Spread the frosting evenly over the cooled lemon brownies. Slice and serve.
Did you make this recipe?
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What the Test Kitchen had to say about this recipe:
Autumn
I love the lemon ermine frosting on top of these lemon bars. So lemony and delicious!
Elizabeth
Pucker up! These bars are lemony, but in the best way! If you love lemon desserts, you will love these.
Annabelle
The lemon 'brownie' texture is moist and dense, just what a brownie should be. And the frosting adds even more lemon flavor. Perfect.
Bella
I’m not usually a big lemon fan, but these were amazing! The brownies are soft and chewy, and the frosting makes them extra great!
Stephanie
The lemon flavor really shines in these! They have just the right balance of sweetness, and the ermine frosting is so smooth and light.
