Noah's Reservoir Mill Recipe

Preheat & Prepare Pan

Preheat the oven to 350°F (175°C). Lightly grease a 9-inch (23 cm) round cake pan or springform pan and line the bottom with parchment paper.

Mix Dry Ingredients

In a large mixing bowl whisk together the all-purpose flour, granulated sugar, baking powder, and fine sea salt until evenly combined.

Combine Wet Ingredients

In a separate bowl whisk the whole milk, Greek yogurt, eggs, melted butter, and vanilla extract until smooth and slightly frothy.

Finish Batter

Make a well in the dry ingredients and pour in the wet mixture. Gently fold with a spatula until just combined — small lumps are fine. Do not overmix to keep the cake tender.

Prepare Blueberry Compote (if not using ready-made)

If using fresh or frozen blueberries, place 1 cup of berries in a small saucepan with the light brown sugar and lemon zest. Cook over medium heat until berries release juices, 4–6 minutes. Mix the cornstarch with the cold water to make a slurry and stir into the berries. Continue to simmer until the mixture thickens slightly, about 1–2 minutes. Remove from heat and let cool to warm (not hot). Taste and adjust sugar or lemon as needed.

Create the Reservoir

Pour about two-thirds of the batter into the prepared pan and spread it to the edges. Spoon the blueberry compote into the center of the batter, leaving a 0.5–1 inch ring of batter at the edge so the filling sits like a 'reservoir' in the middle.

Swirl

Dollop the remaining batter around the blueberry pool and use the tip of a knife or skewer to make a few gentle swirls from the center outward — enough to create a marbled appearance but not so much that the compote mixes through completely.

Sour Cream Drizzle

Whisk together the sour cream, powdered sugar, and fresh lemon juice until smooth. Spoon small amounts over the top of the cake in a loose pattern, then gently spread with an offset spatula to thinly coat exposed batter edges without disturbing the reservoir too much.

Add Texture

Sprinkle the toasted sliced almonds evenly over the top and, if desired, scatter a little coarse turbinado sugar for crunch and sparkle.

Bake

Bake in the preheated oven 30–38 minutes, rotating the pan halfway through, until the cake is golden, the edges are set, and a toothpick inserted into the cake portion (not the blueberry center) comes out with only a few moist crumbs. If the top browns too quickly, tent loosely with foil.

Cool & Set

Remove the cake from oven and place on a wire rack. Let cool in the pan 15–20 minutes to allow the reservoir to settle, then carefully run a knife around the edge and release from the pan. Cool completely on the rack (at least 1 hour) so the filling firms slightly.

Serve

Slice and serve at room temperature or slightly chilled. Leftovers keep covered in the refrigerator up to 3 days. Bring to room temperature before serving for best texture.