When using frozen berries in your baking always add them to the mixture straight from the freezer.

Frozen berries won't 'bleed' their colour while if you thaw them before using they will streak your cakes and muffin mixtures and make them an ugly purple colour.

Also, if the berries are added while still frozen, they will remain as nice whole berries once baked rather than collapsing.

Keep in mind too, the coolness of the berries will cause the batter to become quite thick as you combine the ingredients, but don’t worry about this, it will still bake well.