These cakes can be made the day before, but frost just before serving. Preheat oven to 180°C. Line 18 holes of two standard-size muffin tins with paper cases. Put butter and sugar in the small bowl of an electric mixer and beat until pale and creamy. Add eggs, beating after each addition until just combined. Transfer mixture to a large bowl.
Sift flour and cinnamon on top of butter mixture. Add milk and maple syrup. Stir until combined and smooth. Sprinkle ½ cup frozen blueberries over top of mixture and stir through lightly.
Spoon mixture into paper cases until three-quarters full. Sprinkle remaining blueberries on top of cake mixture. Bake for 20-25 minutes or until a skewer comes out clean when inserted into cakes. Leave in tins for 10 minutes before turning out onto a wire rack to cool.
Make the creamy frosting; put the marscapone, cream and icing sugar in the small bowl of an electric mixer and beat until firm peaks form and mixture is thick enough to pipe.
Fill a large piping bag fitted with a 1cm star pipe with creamy frosting and pipe cream on top of cakes. Keep cakes in fridge until ready to serve and decorate.
Combine jam and enough water for a runny consistency. Sieve mixture to remove fruit pieces. Finish by drizzling jam over top of cream to serve.