Here are the recipes for different Easter cake glazes.
Whisk a room temperatured egg white with the powdered sugar at a low mixer speed (the amount of the powdered sugar depends on the weight of the egg white and the desired thickness of the glaze).
Powdered sugar based glaze
Mix the powdered sugar with 2-3 tbsp. boiling water or lemon juice with a whisk until smooth (the glaze should have no lumps).
Combine the marshmallows with water, and melt the mix in the microwave with short impulses (2 to 3 times for 15 to 20 seconds). You can paint the glaze with gel dye if you wish.
Melt the white chocolate in a water bath or in a microwave (the amount of chocolate depends on the number and the size of the cakes), and cool it to 28-30C (82 to 86F); cover the Easter cakes with the glaze.
All the glaze versions should be applied on the cakes immediately, before they harden.