Pre-heat your oven to 400°F and line a muffin tin with cups or spray with non-stick spray.
Melt your butter in the microwave or a saucepan and add to a large bowl.
Add the cold milk to the butter to cool it before adding in the eggs.
Add in the eggs, sugar, and vanilla extract and whisk to combine.
Sprinkle the flour over the wet mixture. Do not stir yet.
Sprinkle the baking powder and salt over the flour then mix everything together until you see no more dry flour. Do not over-mix.
Roughly chop the raspberries to break them up slightly then add them too the batter. Fold in gently.
Scoop batter into the prepare muffin tins and fill each about ¾ of the way up.
Mix together the 2 tablespoons of sugar and cinnamon and sprinkle over each muffin.
Place in the oven and immediately lower the heat to 350°. Bake for 16-18 minutes or until a toothpick comes out clean. (These will not get dark on top so the best way to check is the toothpick test)