1 Finely chop ginger and mix in a bowl with whole wheat flour, cream of tartar, sugar and a pinch of salt.
2 Add butter, mineral water and eggs and mix with a hand blender until batter is smooth.
3 Rinse and dry raspberries. Line a 12-well muffin tin with baking cups. Fill wells half full with batter, put two raspberries in each well and top with remaining batter. Bake in a preheated oven on middle oven rack at 200°C (fan: 180°C, gas mark 3)(approximately 400°F/convection 350°F) for about 20 minutes.
4 Remove muffin tin from oven and let cool for about 5 minutes. Then transfer muffins to a wire rack and let cool completely for about 40 minutes.
5 Blend sour cream with carob bean powder and vanilla sugar in a bowl until smooth and season to taste with sweetener. Spread cream on muffins and top with remaining raspberries.