Preheat the oven to 350°F (180°C). Grease an 8-inch (20cm) pan and line with parchment paper.
In a medium bowl, whisk together flour with baking powder, baking soda and salt.
In a large bowl, whisk oil with honey until combined.
Add unsweetened applesauce and mix to combine.
Add yogurt, buttermilk, vanilla extract and lemon juice or vinegar.
Mix to combine.
Gradually mix in the flour mixture.
Don’t overmix. Set aside.
Cut the apples into small cubes.
In a bowl, toss the apples with 1 tablespoon of flour, cinnamon and nutmeg.
Using a spatula, gently fold the apples into the batter.
Pour the batter into the prepared pan.
Smooth the top.