Preheat oven to 180°C (350F) or 160°C fan-forced. Grease and line a 20cm round cake pan.
Cream together ricotta cheese, sugar, lime rind and coconut extract. Mix until smooth and creamy, them add egg yolk. In another bowl, mix flour and coconut macaroon crumbs. Fold in the flour mix alternatively with the milk until combined. Beat egg whites to firm peaks. Fold egg whites into the cake mixture. Spoon into prepared pan and sprinkle throught frozen raspberries. Spread batter evenly around pan.
Bake for about 50 minutes or until a toothpick comes out clean. If the cake starts to get too dark, cover with foil while baking.
Leave in the cake pan five minutes before taking out and cool on a wire rack. Dust with icing sugar for serving.