Method

• Heat the oven to 350°F (175°C). Grease an 8-inch square metal pan with the neutral oil. Core the apples and dice them into roughly 1/4-inch pieces. Leave the skin on for this version; measure 2 cups of prepared apple.
• In a large bowl, stir together the rolled oats, baking powder, cinnamon and salt. Break up visible clumps of baking powder so the seasoning and leavening are evenly distributed.
• Whisk the milk, eggs, tahini, maple syrup and vanilla in a second bowl until the tahini is fully dispersed. Stir a jar of tahini thoroughly before measuring it; unmixed oil and dense sesame paste will not behave like a smooth portion of tahini.
• Pour the wet mixture into the oat mixture and stir. Fold in the diced apples. Transfer to the greased pan, distributing the oats and fruit evenly. The mixture looks quite loose before baking; the oats need that liquid to hydrate.
• Bake for 30–40 minutes, starting checks at 30 minutes, until the edges are golden and the center is set with no pool of liquid. A knife inserted near the center should show moist oats rather than runny egg mixture. If the top browns too quickly, loosely cover it with foil and continue checking the center.
• Rest for 10 minutes before dividing into 6 portions. Spoon soft portions onto a plate or cut firmer portions with a thin spatula. Do not expect the crumb or clean edges of a flour-based cake.