1. Preheat the oven to 400°F (200°C). Line a 12-cup muffin pan with paper liners. Combine the apple, ¼ cup brown sugar, and the lemon juice in a bowl, and mix until the apple pieces are evenly coated. Set aside for 5 minutes.

2. Meanwhile, whisk together the flours, baking powder, pumpkin-pie spice, and salt in a large bowl. Mix in the remaining brown sugar and pecans.

3. Whisk together the milk, oil, and egg, then add the apple mixture. Pour into the dry ingredients and stir until just mixed.

4. Divide the batter among the muffin cups, filling them about two-thirds full. Sprinkle with the turninado sugar. Bake for 20–25 minutes, until the tops are rounded and light brown. Immediately unmold the muffins onto a wire rack. Serve hot, warm, or at room temperature.