Sweet Potato Brownies (Ultra Fudgy)

There’s a reason these brownies disappear before they’re cool: the mashed sweet potato melts into the batter, giving plush, fudgy centers without tasting “veggie.” You’ll get glossy tops, clean slices, and the kind of chocolate flavor that satisfies in two bites… even if you go back for a third.

If you’ve been disappointed by cakey or dry attempts, this version fixes that. By the end, you’ll know the exact ratio for fudgy (not gummy) brownies, the doneness cue that matters more than a toothpick, and how pan size changes the texture. I’ll also show you flavor twists and how to store them for lunchbox-perfect squares.

Why This Recipe Works (The Tested Formula)

We combine cocoa powder for deep chocolate plus a bit of melted chocolate for body and sheen. Sweet potato (mashed) adds moisture and binding, letting us use less flour so the crumb stays moist and dense. The tested ratio per 20 cm square pan (8×8 in) is: 200 g mashed sweet potato (about ¾–1 cup), 150 g brown sugar (¾ cup packed), 115 g dark chocolate (about ⅔ cup chips), 113 g unsalted butter or 100 ml neutral oil (½ cup), 2 large eggs, 60 g all-purpose flour (½ cup), and 30 g cocoa (⅓ cup). Bake at 175 °C/350 °F until the center hits ~90–92 °C/195–198 °F or a skewer comes out with moist crumbs.

Most people overbake—pulling at a clean toothpick gives dry edges by the time carryover heat finishes the bake. Aim for faintly wet crumbs in the center and set, shiny top. For a cozy drizzle on sliced brownies, our brown sugar syrup adds a caramel note without hardening.

Ingredients for Sweet Potato Brownies

This is a pantry brownie. Cook a sweet potato in advance (microwave, steam, or roast), mash, and you’re halfway there. We keep flour low and cocoa high for maximum fudge.

• Mashed sweet potato — 200 g (about ¾–1 cup; from 1 medium cooked)
• Dark chocolate (50–60%) — 115 g (about ⅔ cup chips or chopped)
• Unsalted butter — 113 g (½ cup) or neutral oil — 100 ml (½ cup)
• Light or dark brown sugar — 150 g (¾ cup, packed)
• Large eggs — 2 (room temp)
• Cocoa powder (natural or Dutch) — 30 g (⅓ cup)
• All-purpose flour — 60 g (½ cup) (GF: use a 1:1 gluten-free blend by weight)
• Vanilla extract — 2 tsp
• Fine salt — ½ tsp
• Optional: espresso powder — ½ tsp (boosts chocolate), flaky salt for finish

Swaps that work:
• Dairy-free? Use oil and dairy-free chocolate.
• Lower sugar? Reduce to 120 g (½ cup + 1 tbsp) brown sugar; expect slightly less gloss.
• Canned sweet potato or pumpkin works—drain well and measure by weight.

How to Make Sweet Potato Brownies (Step by Step)

Line a 20 cm (8×8 in) metal pan with a parchment sling. Lightly grease. Preheat oven to 175 °C/350 °F, rack center.

Melt & base: In a medium bowl, microwave butter and chocolate in 20–30 second bursts until just melted and smooth. Whisk in brown sugar while warm, then whisk in mashed sweet potato, vanilla, and salt until glossy.

Eggs & dry: Whisk in eggs one at a time until the batter thickens and looks satiny. Sift in cocoa and flour; fold gently just until no dry streaks remain. Overmixing = cakier crumb.

Bake: Spread into pan (batter will be thick). Bake 22–28 minutes. Edges should be set and slightly pulling away; the center should wobble faintly. Internal temp at the middle: ~90–92 °C/195–198 °F. A skewer should have moist, fudgy crumbs—no wet batter.

Cool & slice: Cool in pan 20 minutes, then lift out and cool 40+ minutes before slicing 16 squares. For cleaner cuts, chill 30 minutes. Serving these after a savory night like air fryer chicken wings? Sprinkle flaky salt to echo those savory notes.

Pan size note: A 23 cm (9×9 in) pan bakes faster (18–22 min) and yields slightly thinner brownies. A glass pan may need +3–5 minutes. If the top darkens too quickly, tent loosely with foil for the last 5 minutes.

Pro Tips & Troubleshooting

• Pull at ~90–92 °C/195–198 °F in the center for fudgy, not raw. Cleaner toothpick = drier brownies.
• Room-temp eggs whip better. If cold, set in warm water 5 minutes.
• Measure by weight. Sweet potato density varies; 200 g keeps texture consistent.
• Cakey center? You likely over-mixed the flour/cocoa. Fold just until combined.
• No glossy top? Sugar may not have fully dissolved into the warm fat; whisk longer while the mixture is warm, or use part granulated sugar (replace 30 g of brown sugar).
• Extra fudgy hack: Swap 15 g (2 tbsp) of flour for 15 g (2 tbsp) cocoa.

Variations & Budget-Friendly Ideas

Want different vibes with the same base? Here are tested tweaks:

• Walnut Crunch: Fold in 80 g (¾ cup) chopped walnuts; bake 24–28 min.
• Chocolate Chunk Sea Salt: Add 90 g (½ cup) chopped dark chocolate; finish with flaky salt.
• Mocha Swirl: Whisk 1 tsp espresso powder into the wet mix; drizzle 2 tbsp brown sugar syrup in figure-8s before baking.
• Pumpkin Patch: Swap sweet potato with 200 g pumpkin purée; add ½ tsp cinnamon + ¼ tsp nutmeg.
• Party Slab (9×13 in): 1.5× the recipe; bake 25–32 min.
• No-Oven Dessert Night: Pair these with our no-bake Boston cream pie bars for a chocolate-vanilla spread.

Storage, Make-Ahead & Reheat

• Room Temp: Airtight up to 3 days. Place parchment between layers to keep tops glossy.
• Fridge: 5–6 days, wrapped well; bring to room temp for best texture.
• Freezer: Wrap individual squares in parchment + foil, then bag; freeze up to 2 months. Thaw at room temp 1–2 hours.
• Reheat: 160 °C/325 °F oven for 5–7 minutes to revive fudginess; or 10–15 seconds in the microwave per square.
• Lunchbox tip: Pack from chilled; they soften to perfect by midday.

FAQs

Why aren’t my sweet potato brownies fudgy?

Likely overbaked or too much flour. Bake to 90–92 °C / 195–198 °F and weigh 60 g flour.

Can I use oil instead of butter?

Yes—100 ml oil keeps them ultra-moist; butter gives richer flavor and slightly firmer slices.

Can I use canned sweet potato or pumpkin?

Yes—drain well and measure 200 g. Pumpkin is a touch less sweet; consider +15–20 g sugar

Sources & Further Reading

• King Arthur Baking — Accurate measuring by weight vs. volume helps brownie texture stay consistent.
• Serious Eats — Why sugar dissolved in warm fat promotes glossy, crackly brownie tops.
• USDA Food Safety — General guidance on safe handling of eggs and storage times for baked goods.

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