Frosted Vanilla Brownies

These frosted vanilla brownies are chewy, tender, and topped with silky vanilla buttercream. Also known as blondies, these sweet dessert bars are buttery, moist, and full of vanilla flavor. They're a fun twist on classic fudgy chocolate brownies!

I've never met a brownie I didn't like. They're one of my sister's favorite foods and they're definitely one of mine too. Oreo brownies, red velvet brownies, peanut butter, cheesecake; they're all delicious.

Blondies are basically brownies without chocolate, but I'm calling these vanilla brownies because they still have an incredibly fudgy, gooey, chewy texture. Sometimes blondies can be a little cakey, but these aren't at all. To make them even better, they're topped with the best vanilla frosting ever. I'm going to vanilla heaven!

If you' a brownie lover, check out my almond brownies, olive oil brownies, and salted brownie crinkle cookies!

Why This Recipe Works

• Quick and easy to make- You can make the brownies in one bowl! It's super easy to make with kids.
• Ultra rich and chewy texture- The brownies are extra dense and fudgy because of the extra egg yolk. I used the same base recipe for these maple blondies!
• Pure vanilla flavor- There's no almond extract or white chocolate chips in this recipe. Pure vanilla extract and vanilla bean paste are the only flavorings, making the brownies a vanilla-lovers dream.

Ingredient Notes

• Unsalted butter- Since we are melting the butter, it doesn't have to be at room temperature when you start! Just let it cool a bit after melting in the microwave.
• Granulated sugar- I used cane sugar to highlight the vanilla flavor.
• Eggs and egg yolk- An extra egg yolk makes the brownies super moist and gives them structure without using cornstarch. Pull them out an hour before baking.
• Flour- Use all purpose flour or measure-for-measure gluten free baking flour. I like Bob's Red Mill and King Arthur.
• Vanilla extract- Use pure vanilla extract, not imitation vanilla or anything with artificial flavors. It can be clear or brown. My favorites are from Nielsen-Massey, Beyond Good, and Penzey's.
• Vanilla bean paste- This adds beautiful vanilla bean flecks to the brownie and the frosting and has a strong vanilla flavor. Mine is from Nielsen-Massey.

For the full ingredient list, see the recipe card below

Helpful Equipment and Tools

• Mixing bowls- I love my Duralex nesting bowls. They're heat-proof and dishwasher safe.
• Square baking pan- I like this one from USA Pan because of it's flat, harsh edges. This makes it easy to clip parchment paper to the sides so you can easily lift bars out. The 8x8 inch and 9x9 inch pans both work.

Step by Step Instructions

Preheat the oven to 350°F and spray a square baking pan with non-stick spray. Then, line it with parchment paper.

Step 1: Melt the butter. First, microwave the butter in a bowl for about 1 minute or until it is completely melted. Stop the microwave and stir every 30 seconds so it doesn't explode. Then, let it cool for about 5 minutes.

Step 2: Mix the wet ingredients. In a large mixing bowl, whisk the melted butter and sugar together. Then, add the egg and egg yolk one at a time. Mix in the vanilla and vanilla bean paste.

Tip: Mix the wet ingredients well, but mix the dry ingredients until just combined.

Step 3: Add the flour. In a separate bowl, whisk the flour and baking powder together. Then, fold the dry ingredients into the wet until just combined.

Step 4: Bake the bars. Pour the batter into the prepared baking pan, smooth it out, and bake. The brownies should look slightly underdone. Let them cool completely before removing from the pan and frosting.

Making the Buttercream

Step 5: Cream the butter. Using your stand mixer with the paddle/whisk attachment or electric hand mixer, cream the butter on high for 5-8 minutes. Stop the mixer to scrape down the sides of the bowl as needed.

Step 6: Beat in the powdered sugar and vanilla. Beat in half of the powdered sugar on low for 3 minutes. Then, add the other half of the powdered sugar and the vanilla bean paste and mix on low for another 3 minutes. This helps eliminate air bubbles.

Step 7: Add the heavy cream. Once all the powdered sugar is incorporated, add the cold heavy cream until the desired consistency is reached. The buttercream should have soft peaks.

Step 8: Frost the brownies. Spread the buttercream on top of the cooled brownies with the back of a spoon (an icing spatula or butter knife also work). Cut into squares and serve.

Expert Baking Tips

• Measuring the flour correctly- Measure the flour with a kitchen scale or use the spoon and level method. Spoon flour into the measuring cup until it is full and swipe the excess back into the bag.
• Don't overmix! Fold the flour in until there are no dry spots.
• Check for doneness- When the brownies are done baking, they will look gooey and sink slightly. If they're super sunken, they need more baking time. If they didn't sink, they're overbaked.
• Make sure they're cool Let the vanilla brownies cool completely before frosting, about 1-2 hours. The buttercream will melt and slide off if they are too hot.

Frequently Asked Questions

Storage Instructions

If you didn't frost the brownies, they can be stored on the counter in an airtight container for up to 5 days. They can be refrigerated if frosted for up to 5 days.

Leftover frosting can be stored in an airtight container for up to 5 days. Add a couple tablespoons of milk if it gets dry or clumpy.

Freezing Instructions

Freeze the brownies in an airtight container or wrapped in plastic wrap for up to 30 days. Thaw in the refrigerator an hour before eating.

Leftover frosting can be frozen for up to 30 days and thawed in the refrigerator the night before using.

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