Preheat the oven to 180°C/fan 160°C/gas mark 4. Line a 12-hole muffin tin with squares of baking paper.
Beat the eggs together with the milk and crème fraîche. Stir through the ham, Cheddar and spring onions and set aside.
Divide the baguette pieces between the muffin-tin holes, then spoon over the egg mixture. Let sit for about 30 minutes to allow the egg mixture to soak into the bread. Bake the stratas for 30-35 minutes until golden and a skewer comes out clean.