I’m back on the brownies this week, putting a spooky twist on a super easy brownie recipe. These spiderweb brownies are the sweet spot between cakey and fudgy – rich in chocolate flavour, soft in the middle and ready in under an hour. No fancy kit needed, and yes – you can make the marshmallow cobwebs even if you don’t have a microwave!

Whether you’re baking for a weekend treat, a bake sale or a Halloween party – this is the recipe to bookmark.

Why You’ll Love This Recipe

Perfect for Halloween – These brownies are the ideal last-minute Halloween bake. The spiderweb topping gives them a spooky twist with barely any effort.

Fun for kids (and grown-ups) – Stretching the marshmallow webs is half the fun! It’s a great one to make with kids or for party prep.
No fancy tools needed – You don’t need a piping bag, microwave or special kit – just marshmallows, a stovetop, and your hands.
Rich and chocolatey – Under the cobwebs is a classic fudgy brownie that tastes as good as it looks.

Easy to customise – Add Halloween sprinkles, edible eyes or even sandwich a fondant spider on top for extra fun.

Ingredients Breakdown

For the Brownies:

Butter – For richness and that classic brownie texture.

Light brown sugar – Adds depth and moisture with a subtle caramel note.
Eggs – Help create a slightly fudgy, slightly cakey texture.
Vanilla extract – Brings out the chocolate flavour.

Cocoa powder – Use unsweetened cocoa powder for a rich chocolatey taste.
Plain flour – Just enough to bind the batter without making it cakey.
Salt – Balances the sweetness and enhances the chocolate flavour.

Chocolate chips – Add even more gooey texture and melt-in-the-mouth bites.

For the Spiderwebs:

Marshmallows – Just a handful, melted and stretched into spooky webs. No microwave? Gently melt them in a pan on the hob with a tiny splash of water.

How to Melt Marshmallows for Spiderwebs Without a Microwave

You’ll need:

5-6 large marshmallows (or 50 grams handful of mini ones)
A small saucepan

A heatproof bowl that fits over the saucepan (to make a bain-marie/double boiler)

Step-by-step:

Set up a bain-marie (double boiler):
Fill a saucepan with about an inch of water and bring it to a gentle simmer over low heat. Place the heatproof bowl on top, making sure the bottom doesn’t touch the water.

Melt the marshmallows
Add the marshmallows to the bowl and stir constantly with a silicone spatula or spoon as they start to melt. This should only take a couple of minutes.
Cool briefly
Take the bowl off the heat and let the melted marshmallow cool for about 30 seconds. It should be cool enough to touch, but still very stretchy.

Stretch and decorate
Use your fingers (lightly oiled or wet if needed) to pull and stretch strands of marshmallow across your brownies to create the spiderweb effect.

Tips:

Work quickly – the marshmallow starts to set as it cools.

Keep your fingers wet – the marshmallow doesn’t stick then!
If it firms up too much, you can gently reheat it over the pan for a few seconds to soften again.
Either slice your brownies beforehand, wait until the marshmallow has cooled completely or cut using a wet knife.

Spiderweb Brownies

These Spiderweb Brownies are the ultimate easy Halloween treat! Rich, chocolatey brownies are topped with spooky marshmallow webs – no piping bags needed. Perfect for Halloween parties, trick-or-treat trays or baking with the kids.

Print Recipe Pin Recipe

Prep Time:15

Cook Time:25

Cooling Time:15

Total Time:55

Course: Dessert

Cuisine: American

Keyword: Brownies, Chocolate Brownies, Easy Brownie Recipe, Fudgy Brownies, Halloween Brownies

Servings:

Equipment

Large Bowl
Weighing Scales
Small saucepan

8 inch cake tin (square)
Greaseproof Paper
Small Bowl

Whisk

Ingredients

140 grams unsalted butter (10 tablespoons)
200 grams soft light brown sugar (1 cup, packed)

2 medium eggs
1 teaspoon vanilla extract
40 grams cocoa powder (1/2 cup)

80 grams plain flour (2/3 cup)
1/4 teaspoon fine salt
100 g dark chocolate chopped or chips (about 2/3 cup)

75 grams optional – milk or white chocolate chunks (about 1/2 cup)

Instructions

Preheat the oven to 180°C (160°C fan) / 350°F. Grease and line an 8-inch square tin with baking paper.
In a large mixing bowl, melt the butter – either in the microwave or gently on the hob over a pan of hot water.

Stir in the sugar while the butter is still warm. Mix until glossy and well combined.
Add the eggs and vanilla, then whisk by hand or with a hand whisk for about 30–60 seconds until the mixture lightens a little in colour.
Sift in the cocoa powder, flour and salt. Stir gently until no dry spots remain – don’t overmix.

Fold in the chopped chocolate and any optional extras. The batter will be thick and glossy.
Spoon the batter into your prepared tin, spread it out evenly and smooth the top.
Bake for 25–30 minutes, or until the edges are set and a skewer inserted into the middle comes out with a few moist crumbs.

Leave to cool in the tin for at least 15 minutes.
Place the marshmallows in a heatproof bowl and microwave in 10–15 second bursts until melted and gooey. Stir with a spoon or fork to help them melt evenly.
Let them cool slightly. Wait about 30 seconds – just until the marshmallow is cool enough to touch but still stretchy.

Use your fingers to pinch a bit of the melted marshmallow and stretch it out into thin strands. Drape and pull it across the top of the brownies in random criss-cross patterns to mimic spiderwebs. Keep going until you’re happy with the look!
Stick on some candy eyeballs or chocolate spiders while the marshmallow is still sticky.