To be sure you'll have moist blueberry muffins, start heating the oven to 180°C (160° fan) 350°F gas 4. Place paper cases in a 12 hole muffin tin.
Toss the blueberries in 2 tablespoons of the flour. Set aside.
Beat the butter and sugar together in a mixing bowl until light and fluffy. Beat in the egg.
Sift in the flour, baking powder, bicarbonate of soda and salt and stir until just combined. 5 Gently stir in the soured cream and blueberries.
Spoon into the paper cases and sprinkle with the crushed sugar cubes.
Bake for 20 minutes until the muffins are golden and springy to the touch. Place on a wire rack to cool completely: your moist blueberry muffins are ready to be enjoyed!