Ingredients
For the Cake Batter
- 2 cups all-purpose flour.
- 1 cup sourdough discard (unfed).
- 1 cup granulated sugar.
- 1/2 cup unsalted butter, melted.
- 2 large eggs.
- 1/2 cup whole milk.
- 2 teaspoons baking powder.
- 1 teaspoon vanilla extract.
- 1/2 teaspoon salt.
For the Cinnamon Swirl
- 1/2 cup unsalted butter, softened.
- 3/4 cup light brown sugar, packed.
- 1 tablespoon ground cinnamon.
- 1 teaspoon all-purpose flour.
For the Vanilla Glaze
- 1 cup powdered sugar.
- 2 tablespoons whole milk.
- 1 teaspoon vanilla extract.
Optional Ingredients
- 1/2 cup chopped pecans.
- 1/2 cup chopped walnuts.
- 1/2 cup mini chocolate chips.
- Pinch of nutmeg.
- Cream cheese frosting instead of vanilla glaze.
Ingredient Substitutions
- Replace whole milk with 2% milk or unsweetened almond milk.
- Use salted butter and reduce the added salt by half.
- Greek yogurt can replace half of the butter for a lighter cake.
- Gluten-free 1:1 baking flour works well for a gluten-free version.
- Dark brown sugar can be used for a deeper caramel flavor.
Equipment Needed
- 9 x 13-inch baking dish.
- Large mixing bowl.
- Medium mixing bowl.
- Measuring cups.
- Measuring spoons.
- Silicone spatula.
- Whisk.
- Electric hand mixer (optional).
- Butter knife or skewer for swirling.
- Cooling rack.
- Small bowl for glaze.
- Wire whisk.
- Oven mitts.
Step-by-Step Instructions
Step 1: Prepare the Baking Dish
Preheat your oven to 350°F. Grease a 9 x 13-inch baking dish with butter or nonstick cooking spray. This helps the cake release easily after baking.
Step 2: Mix the Cake Batter
In a large bowl, whisk together the melted butter and sugar until smooth. Add the eggs one at a time, then stir in the vanilla extract, milk, and sourdough discard.
Add the flour, baking powder, and salt. Mix only until no dry flour remains. Overmixing can make the cake dense instead of soft and fluffy.
The batter should be thick but easy to spread.
Step 3: Make the Cinnamon Filling
In a separate bowl, combine the softened butter, brown sugar, cinnamon, and flour until it forms a smooth paste.
If you’re adding chopped nuts, mix them into the filling now.
Step 4: Assemble the Cake
Spread the cake batter evenly into the prepared baking dish.
Drop spoonfuls of the cinnamon mixture over the batter.
Use a butter knife or skewer to gently swirl the filling through the batter. Don’t overmix. A few beautiful cinnamon ribbons create the best texture.
Step 5: Bake
Bake for 35 to 40 minutes.
The cake is done when.
The top is lightly golden brown.
The center springs back when gently touched.
A toothpick inserted into the middle comes out with just a few moist crumbs.
Avoid baking too long because the cake can become dry.
Step 6: Cool
Let the cake cool in the pan for about 15 minutes.
Cooling slightly allows the crumb to set while keeping the inside moist.
Step 7: Prepare the Glaze
Whisk together the powdered sugar, milk, and vanilla until smooth.
If the glaze seems too thick, add a teaspoon of milk at a time.
Step 8: Finish and Serve
Drizzle the glaze evenly over the warm cake.
Slice into squares and serve while slightly warm for the best flavor.
Nutrition Facts
Cost To Make This Recipe
Item – Estimated Cost (USD).
All-purpose flour – $0.60.
Sourdough discard – $0.30.
Granulated sugar – $0.50.
Unsalted butter – $2.20.
Eggs – $1.00.
Whole milk – $0.30.
Baking powder – $0.10.
Vanilla extract – $0.60.
Salt – $0.05.
Brown sugar – $0.50.
Ground cinnamon – $0.25.
Powdered sugar – $0.50.
Estimated Total Recipe Cost
Approximately $7.45 USD.
Estimated Cost Per Serving
Approximately $0.62 USD per serving.
