Heat a conventional oven to 175 °C. Line a 20 cm round tin. Dice one apple and thinly slice the other.
Mix flour, baking powder, cinnamon and salt. Whisk eggs and sugar, then add oil and yoghurt.
Fold in the dry ingredients and diced apple. Transfer to the tin and arrange apple slices on top.
Bake for 40–50 minutes, checking that a skewer has no wet batter. Cool for 15 minutes in the tin, then on a rack.
Make it work for you
Check that all packaged ingredients are suitable for your dietary needs. Lactose-free dairy still contains milk proteins; use suitable plant-based alternatives if you need to avoid dairy.