Marbled Blueberry Bundt Cake with Lemon Glaze

Did you know that July is National Blueberry Month? It’s also National Ice Cream Month. In other words, July is pretty awesome 🙂

Remember when I told you we were going to do an entire week of blueberry recipes? Well, it’s coming, so get excited! In honor of July being National Blueberry Month next week it’s going to be all blueberries all the time! There’s both sweet and savory goodness coming your way, I can’t wait. Truthfully, when I came up with the idea of doing a blueberry week, I had no idea July was National Blueberry Month so when I subsequently learned about that it was a happy coincidence.

This summer I’ve been buying blueberries like it’s my job (which, I guess it sort of is…). While I’ve been eating some of them as is, a good majority have gone into baking projects. And there have been quite a few of them. Too many, in fact, for blueberry week unless weeks suddenly start having 9 or more days. So we’ll get a jump start on the blueberry fun today before the real party gets started on Monday 🙂 Hopefully you guys are on the same page as me in thinking that there’s no such thing as blueberry overload!

This marbled bundt cake is one of my favorite blueberry recipes I’ve made so far. And admittedly I’m kind of obsessed with bundt cakes but this one really is special. Where so many blueberry bundts simply fold fresh blueberries into the batter right before baking, this one goes the extra step of making a simple blueberry jam which is swirled into the batter two times! It ensures you get fresh blueberry flavor in every single bite as opposed to the occasional whole blueberry every so often. It only take a few extra minutes to make the jam, but it really does make all the difference in the world to the cake.

I think blueberry is always great when paired with citrus, and in this cake it’s lemon that’s used. There’s zest and juice in the batter, as well as a sweet/tart lemon glaze to finish off the cake. I really enjoyed the glaze, but it’s definitely optional – the cake doesn’t need it for flavor or added moisture. You could serve this marbled blueberry bundt for brunch, an afternoon snack or dessert – it’s a great, versatile recipe for summer and the perfect way to celebrate National Blueberry Month!

Marbled Blueberry Bundt Cake with Lemon Glaze
barely adapted from Cook’s Illustrated, May/June 2013

{Note: I halved this recipe and baked the cake in a 6-cup bundt pan so that’s an option if you don’t need a full-size bundt cake. You can use frozen blueberries in the filling, just thaw them completely first.}

Cake
3 cups (15 oz) all-purpose flour
1 1/2 teaspoons baking powder
3/4 teaspoon baking soda
1 teaspoon salt
1/2 teaspoon ground cinnamon
3/4 cup buttermilk, at room temperature
2 teaspoons lemon zest
3 tablespoons fresh lemon juice
2 teaspoons vanilla extract
3 large eggs plus 1 large yolk, at room temperature
18 tablespoons unsalted butter, at room temperature
2 cups (14 oz) sugar

Blueberry Filling
3/4 cup (5 1/4 oz) sugar
3 tablespoons low or no-sugar fruit pectin (I used this brand, the pink box)
pinch salt
10 oz (2 cups) fresh blueberries
1 teaspoon lemon zest
1 tablespoon fresh lemon juice

Glaze
2 cups (8 oz) confectioners’ sugar
3-4 tablespoons fresh lemon juice

Preheat oven to 325 F, with a rack in the lower third. Spray a 12-cup Bundt pan with nonstick cooking spray with flour.

In a large bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon. In a medium measuring cup, whisk together the buttermilk, lemon zest, lemon juice, and vanilla. In a small bowl, whisk the eggs and egg yolk until combined.

In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar on medium speed until light and fluffy, about 3-4 minutes. Scrape down the sides of the bowl, then mix in half of the eggs until incorporated, followed by the remaining egg mixture, again mixing until incorporated. With the mixer on low, alternately add the dry ingredients in 3 additions and the buttermilk mixture in 2 additions, beginning and ending with the dry ingredients and beating just until the batter is well combined. Cover the bowl with plastic wrap and set aside while you make the filling.

To make the filling: Add the sugar, pectin, and salt to a small saucepan and whisk to combine. Add the blueberries to the bowl of a blender or food processor and process until mostly smooth. Transfer 1/4 cup of the puree to the saucepan and add the lemon zest as well. Stir to combine. Set the pan over medium heat and bring to a simmer (about 3 minutes), stirring frequently. The sugar and pectin should be dissolved. Pour the mixture into a heatproof bowl and allow to cool for 5 minutes, then whisk in the remaining blueberry puree and lemon juice. Allow to thicken and set for about 8 minutes.

Transfer half of the cake batter to the prepared pan and spread in an even layer. Use the back of a spoon to create a 1/2-inch-deep well around the center. Add half of the filling into the well, then use a thin knife to completely swirl the filling into the batter. Repeat with remaining half of the batter and filling. Bake the cake for about 60-70 minutes, or until golden brown and a thin knife inserted in the center comes out clean. Transfer the pan to a wire rack and cool the cake for 10 minutes, then turn it out onto the rack to cool completely.

To make the glaze: Add the confectioners’ sugar to a medium bowl. Whisk in 3 tablespoons of the lemon juice, then gradually as much of the remaining tablespoon of juice as necessary (a little at a time) to achieve a thick, pourable consistency. Drizzle over the cooled cake and allow to set before serving the cake.