Step 1

Preheat oven to 190 C/ 375 F and lightly grease a ring cake pan. Set aside.In a medium bowl--and using an electric mixer-- beat sugar, eggs, and butter until creamy.

Step 2

Add sour cream and flour and mix for a couple of minutes.

Step 3

Pour mixture into cake pan.

Step 4

Bake for 20 minutes or until golden brown and cooked through when tested with a skewer.To make the icing, use a standard mixer to beat the egg white until soft stiff peaks are formed.

Step 5

Add lemon juice and sugar and food coloring. Beat for a couple of seconds more.

Step 6

Let the cake cool on a wire rack for about 10 minutes. Then pour the royal icing/glaze onto the cake, sprinkle with chopped pistachios, and decorate as desired.