How long do you Preheat an oven for brownies?

Bake brownies for about 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist clumps clinging to it. There will also be a little batter stuck to the toothpick but it shouldn’t be covered in thick uncooked batter. Take care not to overbake brownies.

Ingredients (US Cups - Metric)

• 2/3 cup unsalted butter
• 5 once semisweet chocolate, coarsely chopped
• 1 cup granulated sugar
• 2 large eggs / 1 large egg yolk
• 1 teaspoon vanilla extract
• 1 and 1/4 cups all-purpose flour, sifted
• 1/4 cup unsweetened cocoa powder, sifted
• 1/2 teaspoon salt

Main Brownie Ingredients

• Butter: is necessary for a rich, chewy brownie.
• Sugar: not only will sugar add sweetness, it will also melt during baking and help with the chewiness.
• Flour: the more flour you use, the cakier a brownie will be. Typically I use 1 cup of flour for super fudgy brownies but for this recipe, I added 1/4 cup more.
• Eggs: the main structure of brownies. I also added an extra egg yolk to get more chewiness.

How To Make Brownies?

STEP 01 - Melt the chocolate and butter

• Preheat the oven to 350°F. Line an 8x8-inch pan with parchment paper or aluminum foil, leaving a 1-inch overhang on all sides. Spray lightly with nonstick spray and set aside.
• In a medium heatproof bowl set over a pot of barely simmering water, melt the chocolate and butter, stirring constantly until the mixture is smooth. You can also microwave in 30-second intervals, stirring between each one.

STEP 02 - Mix in the sugar

It’s important to add the sugar while the melted chocolate is hot. The sugar will melt ensuring the baked brownies aren’t grainy.

STEP 03 - Mix in the eggs and vanilla

Let the chocolate mixture cool before adding the eggs so they don’t scramble. Then whisk them in really well with the vanilla.

STEP 04 -  Mix in the flour and cocoa powder

Add the flour and cocoa powder then use a silicone spatula to fold it in just
until it’s incorporated. Take care not to overmix.

STEP 05 -  Bake

Bake the brownies for 25-30 minutes in a 350°F oven.Use the toothpick test to check for doneness. There should be a little batter and a few moist crumbs clinging to the toothpick.

Whenever I want a warm, chocolatey, decadent dessert, brownies are a solid go-to to satisfy my cravings. 

The problem is that when you make brownies, you can never make just one.

You have to make a whole pan.

I have no problem eating room-temperature brownies, but there’s something extra special about a freshly-baked brownie. 

I guess you think the same, which is why you’re here.

I’ve tested five ways to reheat brownies to determine which one gives me (and you) the best “fresh from the oven” results.

A note on my experiment

To begin, I made two batches of brownies. 

One batch was the standard, original style brownies that have more of a cake-like texture. 

My other batch was what you’d call fudgey brownies – a little gooier, denser, and richer than regular brownies.

After indulging in – I mean “quality testing” – more brownies than I probably should have eaten, I set several brownies from each batch aside to test out some methods for reheating them.

I tried:

• The oven/toaster oven (my favorite)
• The microwave (my partner’s favorite and good for stale brownies)
• An air fryer
• On a toaster (a surprise contender for the top spot)
• In a skillet (worst method, not recommended)

I wanted to recreate the moistness of a freshly-baked brownie and the little bit of crunch you get around the edges.

Reheating brownies in the microwave

To reheat brownies in the microwave, place one or two brownies on a microwave-safe plate. If the brownies are stale, cover them with a damp paper towel. Microwave on HIGH in 10-second intervals until warmed through, about 20 to 30 seconds for one brownie.

How to reheat brownies in the microwave:

1. Place one or two brownies on a microwave-safe plate.
2. If the brownies are on the stale side, cover them with a damp paper towel.
3. Microwave on HIGH in 10-second intervals, for about 20 to 30 seconds total.
4. Let the brownies rest for 30-60 seconds before eating.

I only recommend reheating one or two slices at a time.

Too many slices will result in uneven heating.

Using a damp paper towel will prevent stale brownies from drying out further and can also add back some moisture. 

If you use a damp paper towel on not-so-stale brownies, you’ll get super soft and gooey brownies. 

Watch your total cooking time. 

It’s easy for the brownies to overcook if you let them go too long in the microwave.

My verdict

The original, “normal” brownies came out soft and moist – they were good.

The fudgey brownies came out extremely gooey, almost as if they had melted a bit. I didn’t care for them, but my partner loved them.

Top tip: the microwave works really well for stale brownies.

Reheating brownies in the oven or toaster oven

Preheat your oven or toaster oven to 350ºF (180ºC). Place the brownies on a baking sheet and heat for 5 minutes. If reheating a large slab or an entire batch, cover the baking sheet loosely with a sheet of aluminum foil and bake for 10 to 20 minutes, removing the foil for the last 5 minutes.

If you use a toaster oven you can shave a few minutes of the total heating time.

How to reheat brownies in the oven or toaster oven:

1. Preheat the oven or toaster oven to 350ºF (180ºC).
2. Place brownies on a baking sheet. Cover with foil if reheating a large slab.
3. Heat for 3 to 5 minutes for a single slice, 15 to 20 minutes for a large slab.
4. Remove foil for the last 5 minutes if heating a large slab so the top can crisp up. 

Using aluminum foil for a large slab of brownies helps prevent the brownies drying out too much. 

You don’t need to use it if you’re only reheating a single slice because it won’t be in the oven long enough to dry out.

The total heating time will vary depending on how thick or thin your brownies are.

Also, if you’re reheating brownies from the refrigerator, they’ll take slightly longer than room temperature brownies.

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