Slice each croissant horizontally almost all the way through, leaving one side attached like a hinge.
In a bowl, mix the cream cheese, chopped strawberries, and raspberry preserves until evenly combined.
Spread the berry filling inside each croissant and gently press the halves together.
In a separate bowl, whisk the eggs, milk, vanilla, and cinnamon until smooth.
Heat a large skillet over medium heat and add 1 tablespoon of butter.
Dip each stuffed croissant into the egg mixture, letting excess drip off, then place in the skillet.
Cook for 3 to 4 minutes per side until golden brown, adding the remaining butter as needed.
Serve warm with fresh strawberries on the side.