Blueberry Muffin Cake

Blueberry Muffin Cake, a moist, almondy cake (or muffin?) that answers the question of whether a muffin is cake, or cake is a muffin. Why not have both? If you don't have either a stand mixer or food processor, you can mix the batter by hand in a large bowl with a spoon or spatula. Just expect to use a bit of vigor (or use a pastry blender) to cut the butter into the dry ingredients. If using frozen blueberries, don't defrost them before baking but use them frozen. Tossing them with 1 Tbsp. of flour before strewing them over the top will help keep them from being overly generous with their juices, and also keeps them from sinking to the bottom. I didn't try it in a square cake pan, but if you do, most square pans are a little larger than their round counterparts so the cake will be thinner and will likely bake in less time.

Cake:
1¼ cup all-purpose flour, unbleached (170 g)
1 cup sugar (200 g)
½ cup almond flour (60 g)
1 tsp. baking powder
¼ tsp. kosher salt
10 Tbsp. (5 oz) unsalted butter, cubed, at room temperature (140 g)
2 large eggs, at room temperature
½ cup whole milk, at room temperature (125 mL)
1 tsp. pure vanilla extract
1 lemon, freshly zested
2 cups fresh blueberries (330 g)

Topping:
½ cup walnuts or pecans, untoasted, chopped (60 g)
3 Tbsp. sugar
½ tsp. ground cinnamon
pinch kosher or sea salt
2 Tbsp. (1 oz) unsalted butter, cut into 8 pieces (30 g)

Preheat the oven to 375°F (190°C/170°C fan, Gas Mark 5). Butter an 8" (20 cm) cake pan. Cut a circle of parchment paper about 16" (40 cm) round. Smear it with softened butter, then line in the inside of the cake pan with it, buttered side up, so it covers the bottoms and up the sides of the pan, which you'll use later to help you lift out the cake. Press the paper up against the sides to flatten and smooth away any wrinkles.

To Make the Cake:
In the bowl of a stand mixer fitted with the paddle attachment, stir together the flour, sugar, almond flour, cornmeal, baking powder, and salt. Add the butter and mix on medium speed until the butter is in small pieces, about the size of peas. Add the eggs, milk, vanilla, lemon zest, and mix just until the batter is smooth but avoid overmixing and overbeating it. (The batter can also be made in a food processor by mixing all the above ingredients together until smooth.)

Scrape the batter into the prepared pan. Cover the top with blueberries and use a butter knife to swirl the batter and blueberries together very slightly, just enough to distribute the blueberries and embed them a bit in the batter.

Bake until the top is golden brown, about 45 minutes.

To Make the Topping:
In a small bowl, mix the chopped nuts, cinnamon, ugar, and salt.

Sprinkle the topping over the cake, place the pieces of butter in various places over the top of the cake, and bake until the cake feels just set in the center. A toothpick inserted into the center should come out clean, about 15-25 minutes.

Let the muffin cake cool completely in the pan, then remove it to serve.

Serve the cake on its own, or with plain or slightly sweetened yogurt, ice cream, or whipped cream.

Makes 8 servings.