Preheat oven to 350 degrees F (175 degrees C). Lightly spray a 9-inch round cake pan with cooking spray.

Sift gluten-free baking flour, baking powder, baking soda, and sea salt together in a bowl until well combined.

Combine honey, almond milk, Greek yogurt, 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 batter is just combined.

Pour batter into the prepared cake pan. Scatter raspberries over batter, gently pressing so they stay in place.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 30 to 35 minutes. Cool cake in the pan, about 20 minutes. Invert onto a serving plate. Sprinkle lemon zest on top.