5-Minute Cinnamon Cake

1 + ⅔ cups all-purpose flour
1 cup sugar
1 cup milk
2 teaspoon vanilla (optional)
2½ teaspoons baking powder
pinch salt
large egg
TOPPING
½ cup brown sugar
1 teaspoon cinnamon
¼ cup melted butter
chopped walnuts (optional)

How to make it :

Preheat Oven at 350
Grease a 13x9 pan.
In a bowl mix all cake ingredients and place in pan.
Sprinkle brown sugar,cinnamon; walnuts on top of cake
Drizzle melted butter over top.
Bake for 30 minutes