Lemon Blueberry Sourdough Toast

There's something about the smell of lemon zest hitting hot cast iron that makes you pause mid-morning and think, yes, this is what breakfast should be. I discovered this bake completely by accident when I had half a loaf of sourdough going stale and a punnet of blueberries sitting on the counter, their skins starting to wrinkle just slightly. The custard came together because I wanted something brighter than the usual cinnamon-sugar routine, something that would wake people up without needing coffee first. Now it's become my go-to when I want to impress without actually having to stand at the stove.

I made this for my sister's birthday brunch last spring, and watching her face when she tasted it was worth every minute of prep. She'd been skeptical about the lemon in a French toast situation until that first bite, then she just went quiet. That kind of quiet is why I keep making it.

Ingredients

• Sourdough bread, 1 loaf (about 400 g / 14 oz), cut into 1-inch cubes: The sourness is essential here; it cuts through the richness and keeps this from tasting one-note sweet. Day-old bread is actually your friend because it soaks up the custard without dissolving into mush.
• Fresh or frozen blueberries, 1 ½ cups (225 g): Either works, but frozen berries won't bleed into the custard as quickly, so you get pockets of bright flavor. I've learned to scatter them throughout, not just on top.
• Lemon zest, from 1 lemon: Zest before you juice; I learned this the hard way. The oils in the zest are where the magic lives.
• Large eggs, 6: They're your binder and your lift; don't skip or substitute here.
• Whole milk, 2 cups (480 ml): This is your volume; it soaks into every corner of bread and keeps things custardy instead of eggy.
• Heavy cream, ½ cup (120 ml): The secret to a custard that's velvety rather than thin.
• Granulated sugar, ⅓ cup (65 g) for custard, 2 tbsp (25 g) for topping: Don't lump these together in your head; the custard sugar dissolves completely, the topping sugar stays textured.
• Pure vanilla extract, 2 tsp: Imitation will flatten the flavor; this is where you don't compromise.
• Salt, ¼ tsp: This tiny amount makes the lemon sing and keeps sweetness from being cloying.
• Lemon juice, from 1 lemon: Fresh juice only; bottled tastes like regret.
• Unsalted butter, 2 tbsp (28 g), melted: This carries the cinnamon topping and creates that golden finish.
• Ground cinnamon, ½ tsp: A subtle echo, not a shout.

Instructions

Prepare your baking dish:

Grease your 9x13-inch dish generously; I use butter and my fingers because I can feel where I've covered. Arrange the sourdough cubes in an even layer, then scatter blueberries and lemon zest throughout like you're setting a small treasure map.

Make the custard:

Crack your eggs into a large bowl and whisk them until the yolks and whites are fully married. Add milk, cream, sugar, vanilla, salt, and lemon juice, whisking until smooth and slightly pale; you'll hear the whisk hitting the bowl with a different sound once everything's properly combined.

Soak the bread:

Pour the custard evenly over your bread and berries, then press down very gently with the back of a spatula, watching the bread darken as it absorbs the mixture. You're not mashing; you're encouraging.

Rest and chill:

Cover the dish with plastic wrap and refrigerate for at least 30 minutes, though overnight is genuinely better because the flavors meld and the sourdough gets enough time to fully drink everything in. I set mine up the night before and it's one less thing to worry about in the morning.

Preheat and top:

When you're ready to bake, heat your oven to 350°F (175°C). Drizzle the melted butter over the surface, then mix your sugar and cinnamon together and sprinkle it evenly across the top.

Bake until golden:

Bake uncovered for 45 minutes, checking around the 35-minute mark to see how golden it's getting. You're looking for the center to barely jiggle when you shake the pan and the top to be deep golden brown.

Rest before serving:

Let it cool for 10 minutes; this lets everything set slightly so it holds together when plated. Serve warm with maple syrup, a dusting of powdered sugar, or nothing at all because the lemon custard is plenty.

Save

My neighbor came over one morning and ate three servings, then asked for the recipe, then asked again three weeks later because she'd already made it twice. That's when I knew this wasn't just breakfast; it was the kind of thing that makes people want to gather around a table and linger over coffee.

Why Sourdough Changes Everything

Regular white bread would be fine here, honestly, but sourdough gives you this underlying complexity that makes people pause mid-chew and wonder what they're tasting. The tang works with the lemon instead of against it, and because sourdough has a tighter crumb, it doesn't turn into mush. I've tried other breads out of curiosity and always come back to sourdough; it's worth the trip to a good bakery.

The Lemon Factor

Adding lemon to French toast feels counterintuitive until you taste it, then you wonder why you haven't been doing this all along. It's bright without being sour, and it prevents the whole dish from feeling heavy or one-dimensional. I learned to use both zest and juice because the zest gives you immediate aroma and flavor intensity while the juice dissolves into the custard and creates an underlying brightness.

Make It Your Own

This is one of those recipes that invites tinkering without falling apart; you can swap berries, change your spice profile, or even add a splash of almond extract if that's your thing. The structure is solid enough that small changes enhance rather than derail.

• Try raspberries or blackberries mixed with the blueberries for deeper tartness.
• A pinch of nutmeg in the custard adds warmth without announcing itself.
• Make it dairy-free by using oat milk and coconut cream, which honestly work beautifully here.

Save

This bake has quietly become the breakfast I make when I want people to feel cared for without making a production out of it. It's the kind of dish that does the heavy lifting for you.

Recipe FAQ

→ Can I use other berries instead of blueberries?

Yes, raspberries or blackberries work well and complement the lemon flavor nicely.

→ How long should the custard soak the bread?

At least 30 minutes in the refrigerator allows the sourdough to absorb the custard fully; overnight soaking intensifies the flavor and texture.

→ Can I make this dish dairy-free?

Substitute plant-based milk and cream alternatives to create a dairy-free version without sacrificing creaminess.

→ What's the best way to serve this dish?

Serve warm, optionally topped with maple syrup or a dusting of powdered sugar for added sweetness.

→ How can I achieve a golden, crispy top?

Drizzle melted butter over the surface and sprinkle cinnamon sugar before baking to create a beautiful, caramelized crust.