Fall head-over-heels with these Strawberry Sweetheart Brownies: fudgy, chocolaty squares layered with a swirl of sweet strawberry jam and topped with heart-shaped marshmallows for a playful twist.

They’re an irresistible blend of rich cocoa and bright fruit—perfect for Valentine’s Day, spring picnics, or any time you need a little love in dessert form.

Why You’ll Love This Recipe

Fudgy & Fruity – Luscious chocolate brownie base meets a vibrant strawberry ribbon

Easy One-Bowl Prep – Minimal dishes, maximum indulgence

Festive Presentation – Heart-shaped marshmallows make each square a gift

Customizable – Swap in fresh strawberries, white chocolate chips, or flavored jams

What You’ll Need (Ingredient Highlights)

Unsalted Butter & Bittersweet Chocolate – Melted together to form the ultra-rich brownie base

Granulated & Brown Sugar – Provides shine, chew, and depth of flavor

Large Eggs – Bind and lend that classic brownie fudginess

All-Purpose Flour & Cocoa Powder – Light hand ensures dense, tender crumb

Strawberry Jam – Swirled into the batter for bright, fruity pockets

Heart-Shaped Marshmallows – Toasted on top for a melty, whimsical finish

Vanilla Extract & Salt – Enhance and balance the sweetness

Pro Tips Before You Start

Room-Temp Eggs: For even incorporation and a smooth batter.

Don’t Over-Mix: Fold flour just until combined to avoid cakey brownies.

Warm Jam: Microwave 10 seconds for easy swirling.

Use High-Quality Chocolate: A 60–70% cocoa bar gives optimal richness.

Line Your Pan: Parchment with overhang makes removal and slicing a breeze.

How to Make Strawberry Sweetheart Brownies

Step 1: Preheat & Prep

Preheat oven to 350°F (175°C).

Line an 8×8-inch baking pan with parchment, leaving two sides overhanging.

Step 2: Melt Butter & Chocolate

In a heatproof bowl set over simmering water (or microwave in 20-sec bursts).

Melt ½ cup (115 g) butter with 4 oz (115 g) bittersweet chocolate, stirring until smooth.

Remove from heat.

Step 3: Whisk in Sugars & Eggs

Whisk in ¾ cup granulated sugar and ¼ cup packed brown sugar until glossy.

Add 2 large eggs, one at a time, whisking until fully incorporated.

Stir in 1 tsp vanilla extract.

Step 4: Fold in Dry Ingredients

Sift together ½ cup all-purpose flour, ¼ cup unsweetened cocoa powder, and ¼ tsp salt.

Gently fold into the chocolate mixture until no streaks remain.

Step 5: Layer & Swirl

Pour half the batter into the pan and spread evenly.

Dollop ½ cup strawberry jam in spots, then swirl with a skewer or knife.

Top with remaining brownie batter and repeat with ¼ cup jam, creating pretty ribbons.

Step 6: Top with Marshmallows & Bake

Arrange 12–15 heart-shaped marshmallows evenly on top.

Bake for 25–28 minutes, until edges are set but center still jiggles slightly.

Marshmallows should puff and lightly golden.

Step 7: Cool & Slice

Let brownies cool completely in the pan on a wire rack.

Use parchment overhang to lift out, trim edges if desired, and cut into 9 or 12 squares.

What to Serve With These Brownies

Vanilla Ice Cream – The classic cool-and-warm combo

Whipped Cream & Fresh Berries – Lightens the richness

Espresso or Latte – Bittersweet coffee heightens the chocolate notes

Variations & Substitutions

Fresh Strawberry Layer: Slice fresh berries atop jam before swirling.

White Chocolate Chips: Fold in ½ cup chips for extra sweetness.

Raspberry or Apricot Jam: Swap for a tart contrast.

Gluten-Free: Use a 1:1 GF flour blend and ensure cocoa is GF.

Dairy-Free: Substitute vegan butter and dairy-free chocolate.

Storage & Freezing Tips

Room Temp: Store in an airtight container for up to 3 days.

Refrigerate: Keeps up to 5 days; bring to room temp before serving.

Freeze: Wrap individual squares in plastic and foil; freeze up to 1 month.

Thaw at room temperature.

FAQs

Why are my brownies cakey?
Over-mixing or too much flour—stir gently and measure carefully.

Can I skip the marshmallows?
Yes—sprinkle coarse sugar or chopped nuts on top instead.

How do I know when they’re done?
Edges should look set; center remains a bit jiggle-y for fudgy texture.

Can I use store-bought brownie mix?
Swirl jam into prepared mix and top with marshmallows; bake per mix instructions.

Why didn’t my jam swirl?
Warm it briefly for thinner consistency.

Can I halve the recipe?
Yes—use a 6×6 pan and adjust baking time to ~20–22 minutes.

My marshmallows collapsed—help!
Bake hot and fast (avoid overbaking) so they puff and set quickly.

Final Thoughts

These Strawberry Sweetheart Brownies combine the luscious depth of chocolate with the bright cheer of strawberry, crowned by gooey hearts that evoke smiles.

Whether you’re celebrating love, spring, or simply craving a dessert upgrade, these brownies are sure to win hearts—one fudgy square at a time.