* ingredients:
+For cake you will need following ingredients:
°1 c flour (all-purpose)
°1 c sugar (granulated)
°1⁄4 t salt
°1 butter (4 ounces)
°2 tablespoons cocoa powder (unsweetened)
°Half a cup of boiling water
°Quarter of a cup of milk
°1 scrambled egg
°1/2 tsp  soda
°1 tsp vanilla
°7 tsp un.salted butter, for decorate
°Cocoa powder (about 2 tablespoons)°
°Milk (three tablespoons
°1 teaspoon vanilla
°2 c. sift fine sugar

* Methods : 

Heat oven to 350 degrees F .
Using cooking spray, lightly coat a pot with 1/4 of a sheet of paper. Quarter sheet tray size is 12 x 10 inches.
Make the cake first. Mix the flour, sugar and salt together in a medium bowl.
Melting butter in small skillet on medium-low heat.
Add cocoa powder and hot water after the butter has melted.
Combine milk, eggs, baking soda, and vanilla in a measuring cup.
The curd mixture should be added to the flour mixture first, then the hot water mixture.
All cake ingredients must be mixed well before pouring into the prepared pan.
Cook for 15 to 18 minutes, or until a toothpick inserted into the attachment comes out clean.
Prepare the decorations while baking the cake. Melt the butter in the same saucepan over medium-low heat
Combine cocoa powder, yogurt, and vanilla in a large mixing bowl.
Remove the saucepan from the heat and add the powdered sugar, whisking constantly.
Put the top layer on the cake as soon as it appears on the stove.. Spread the icing on the edges of the pan with an unfastened spoon.
Leave at least 30 minutes for the cake to cool before serving.

Enjoy !