Preheat oven to 180 C / Gas 4. Lightly grease a 23cm round cake tin.
Sift gluten free flour, baking powder, bicarbonate of soda and salt together in a bowl until well combined.
Combine honey, almond milk, yoghurt, egg whites, lemon juice, coconut oil and lemon extract in a large bowl. Stir to combine until no lumps remain. Gently stir in the flour mixture until just combined.
Pour mixture into the prepared cake tin; scatter raspberries on top, gently pressing them in so they stay in place.
Bake in the preheated oven until a skewer inserted into the centre of the cake comes out clean, 30 to 35 minutes. Cool cake in the tin for about 20 minutes. Turn out onto a serving plate; sprinkle lemon zest on top.