Preheat the oven to 190 ̊C / fan 180 ̊C / gas mark 5. Lightly grease or line a muffin tin, or line with muffin cases.
In a bowl, combine the flour,sugar, cinnamon and a pinch ofsalt. Using a hand mixer, stir until all the dry ingredients are well combined.
Pour the liquid ingredients into the dry ingredients and briefly beat. Add the frozen berries and beat until just combined, ensuring not to over beat the batter.
Spoon the batter into each of the muffin cases and sprinkle pumpkin seeds, over each muffin.
Bake for 25 minutes or until the muffins are golden brown on top.
Remove from the oven and allow to cool on a wire rack.