Blueberry Old-Fashioned Donut Loaf

Ingredients

• 115 g (about 3/4 cup + 3 tablespoons + 1 teaspoon) all-purpose flour
• 80 g (about 6 tablespoons + 1 1/2 teaspoons) granulated sugar
• 1/2 teaspoon fine sea salt
• 85 g (about 6 tablespoons) cold butter, cubed
• 1/2 teaspoon vanilla bean paste
• 260 g (about 2 cups + 3 tablespoons) all-purpose flour
• 15 g (about 2 tablespoons + 1/2 teaspoon) cornstarch
• 1 3/4 teaspoons baking powder
• 1/4 teaspoon baking soda
• 3/4 teaspoon fine sea salt
• 1/4 teaspoon ground nutmeg
• 220 g (about 1 cup + 2 tablespoons) granulated sugar
• 26 g (about 2 tablespoons + 1/2 teaspoon) wild freeze-dried blueberry powder
• 120 g (about 1/2 cup + 2 teaspoons) neutral oil
• 200 g (about 3/4 cup + 1 tablespoon) plain unsweetened yogurt, room temperature
• 145 g (about 1/3 cup + 4 tablespoons) milk, room temperature
• 1 tablespoon vanilla bean paste
• 1 teaspoon blueberry emulsion, for a nostalgic blueberry cake donut flavor
• 1/2 teaspoon apple cider vinegar
• 85 g (about 1/2 cup + 2 teaspoons) dried wild blueberries
• 250 g (about 2 cups + 1 tablespoon) powdered sugar, sifted
• 60 g (about 1/4 cup) milk
• 1 teaspoon vanilla bean paste
• Pinch fine sea salt
• Coarse sanding sugar, for sprinkling

Steps

1. Preheat the oven to 350°F (175°C). Grease and fully line a 9x5-inch loaf pan with parchment paper.
2. In a medium bowl, whisk together the flour, granulated sugar, and salt for the streusel. Add the cold butter and vanilla bean paste. Work together with your fingertips until a mixture of fine crumbs and large buttery clusters forms. Refrigerate while preparing the batter.
3. In a large bowl, whisk together the granulated sugar, oil, yogurt, milk, vanilla bean paste, blueberry emulsion, and apple cider vinegar until completely smooth.
4. Add the flour, cornstarch, freeze-dried blueberry powder, baking powder, baking soda, salt, and nutmeg. Whisk just until combined and no dry streaks remain.
5. Fold in the dried wild blueberries just until evenly distributed.
6. Spread just under half of the batter into the prepared loaf pan.
7. Sprinkle half of the chilled streusel evenly over the batter.
8. Carefully spread the remaining batter over the streusel until completely covered.
9. Sprinkle the remaining streusel evenly over the top, leaving plenty of large buttery clusters.
10. Sprinkle the top lightly and evenly with coarse sanding sugar just before baking.
11. Bake for 50-65 minutes, or possibly longer if your oven runs slower. Check the loaf at 45 minutes to see how the streusel is browning and tent loosely with foil if needed. Depending on your oven, the total baking time may extend to 90 minutes. Use the listed doneness cues rather than the clock alone.
12. Before you take the loaf out Baking time is a guide, not a deadline. Check the center: Insert a skewer or toothpick into the cake in the center, avoiding blueberries and the streusel layer. Ready to come out: The center no longer jiggles and the tester comes out clean or with moist crumbs. No wet batter. Keep baking: Thick, paste-like batter: bake 3-5 minutes more. Wet batter: bake 7-10 minutes more. Then test the center again. The 205-210°F (96-99°C) range is an extra check. Batter on the tester still means keep baking, even at that temperature. An underbaked center can collapse as the loaf cools.
13. Cool in the pan for 10-15 minutes, then carefully lift the loaf onto a wire rack.
14. Once the loaf is on the wire rack and feels warm but no longer hot, whisk together the powdered sugar, milk, vanilla bean paste, and salt until smooth and pourable. Spread the glaze evenly over the top, allowing it to naturally drip down the sides.
15. Allow the glaze to set on the counter or in the refrigerator before serving. The loaf can be served warm or fully chilled.