One-Bowl Rhubarb & Rye Muffin Slab: Maximum Crust, Zero Muffin Tins
I remember watching my mother meticulously portion out batter for petits gâteaux in Paris, sighing at the endless mess. When I moved to the Bay Area and started baking with local, aggressively tart rhubarb, I wanted that buttery crumb without the tin hassle. Muffin tins are a trap. We are not suffering for breakfast, but we are also not wasting our Tuesday morning scooping batter into twelve individual cups.This One-Bowl Rhubarb & Rye Muffin Slab is the answer. It mixes in a single bowl and bakes in a quarter-sheet pan. Why a slab? Maximum crust-to-crumb ratio. The high-hydration rye batter creates a lacy crumb—never tight like a bad alibi. The tart rhubarb sinks just enough to jam up, while the heavy hand of turbinado sugar on top shatters when you bite into it.Make it your own by swapping rhubarb for whatever is seasonal; plums or blackberries work beautifully. Look for a golden, wobble-free center and bubbly fruit pockets to know it is done.Cami's shortcut note: Mix the dry ingredients the night before. Let time do the work.Don't skip this: Brown your cultured butter. Butter is not a garnish.
Featured Recipe
One-Bowl Rhubarb & Rye Muffin Slab
We are not suffering for breakfast, but we are also not wasting our Tuesday morning scooping batter into twelve individual muffin cups. This high-hydration rye batter mixes in a single bowl and bakes in a quarter-sheet pan for maximum crust-to-crumb ratio. The tart rhubarb sinks just enough to jam up, while the turbinado sugar shatters when you bite into it.
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Timeline
Ingredients
- 1/2 cup (113g) cultured unsalted butter(melted and slightly cooled)
- 3/4 cup (150g) granulated sugar
- 2 large eggs(room temperature)
- 1 cup (240g) whole milk yogurt(not Greek, you want the moisture)
- 1 tsp vanilla bean paste(or high-quality extract)
- 1 cup (130g) all-purpose flour
- 3/4 cup (85g) dark rye flour(brings a nutty, earthy depth)
- 1 1/2 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp kosher salt(Diamond Crystal)
- 2 cups (250g) fresh rhubarb(chopped into 1/2-inch pieces)
- 3 tbsp turbinado sugar(essential for the crackly crust)
Instructions
- 1
Preheat your oven to 400°F (200°C). Line a 9x13-inch quarter sheet pan with parchment paper, leaving an overhang on the long sides so you can lift the slab out later. Don't skip the parchment; rhubarb likes to stick.
5 min
Tip: A metal pan gives you much better edge crisping than glass or ceramic.
- 2
In a large mixing bowl, aggressively whisk the 1/2 cup (113g) cultured unsalted butter, 3/4 cup (150g) granulated sugar, 2 large eggs, 1 cup (240g) whole milk yogurt, and 1 tsp vanilla bean paste. You want a perfectly smooth, homogenous emulsion before the flour hits the bowl. Let time do the work here—whisk for a solid 60 seconds.
3 min
Tip: If your yogurt was cold, your melted butter might seize into tiny clumps. Don't panic, just keep whisking. It will bake out fine.
- 3
Dump the 1 cup (130g) all-purpose flour, 3/4 cup (85g) dark rye flour, 1 1/2 tsp baking powder, 1/2 tsp baking soda, and 1 tsp kosher salt directly onto the wet ingredients. Fold with a flexible spatula just until the dry streaks disappear. Overmixing here makes the crumb tight like a bad alibi. Stop when it still looks a little shaggy.
2 min
Tip: Rye flour loves hydration, so a slightly lumpy batter is exactly what we want.
- 4
Gently fold exactly half, or 1 cup (125g) fresh rhubarb, into the batter. Scrape the entire mixture into your prepared sheet pan and nudge it into the corners using an offset spatula or the back of a spoon.
2 min
- 5
Scatter the remaining 1 cup (125g) fresh rhubarb evenly over the top, pressing the pieces very lightly into the batter so they anchor. Aggressively shower the entire surface with the 3 tbsp turbinado sugar.
2 min
Tip: The turbinado sugar is non-negotiable. It creates the shatter-crisp crust that separates café-level baking from a sad grocery store muffin.
- 6
Bake on the middle rack for 20-22 minutes. You are looking for visual cues: deeply bronzed edges, a cracked sugary top, and a center that springs back when firmly tapped. A toothpick inserted in the center should come out clean (minus any jammy rhubarb).
22 min
Tip: Watch the color. The dark rye flour means the batter starts out tan, so look for a dark golden-brown finish.
- 7
Use the parchment overhang to lift the slab onto a wire rack. Let it cool for at least 15 minutes before slicing into squares. Slicing too early lets the steam escape, ruining your lacy crumb.
15 min
Tip: Cut into 12 squares. Eat the edge pieces first; they have the best caramelization.
Chef's Notes
Cami's shortcut note: The fridge is your friend. You can mix this entire batter, spread it in the pan, top it, cover it tightly, and leave it in the fridge for up to 3 days. Bake it straight from cold on a weekday morning (just add 3-4 minutes to the bake time) for zero-brainpower prep. The overnight rest actually hydrates the rye flour better, yielding a softer crumb and more complex flavor.
Camille Roux
Café-level bakes, weeknight methods, zero compromise.
Camille “Cami” Roux was born in Paris with flour in her hair and a healthy skepticism of culinary dogma. She grew up around neighborhood boulangeries that treated crust and crumb like religion—but what stuck with her wasn’t rigid tradition. It was the quiet precision: good butter that actually tastes like milk, patient fermentation that builds flavor for free, and desserts that know when to stop before they get cloying. After moving to the Bay Area, Cami trained in a bread-and-pastry scene obsessed with texture, naturally leavened doughs, and seasonal fruit—Tartine energy, minus the martyrdom. She became known for loaves that sing when they cool, jammy tarts with clean edges, and “how is this so good?” weeknight pastries made with a few smart shortcuts. Her motto is high impact, low fuss: splurge where it counts (butter, salt, time), streamline the rest (sheet pans, one bowl, cold-proofing). If it doesn’t improve flavor or structure, it doesn’t earn a step.