1.
Preheat oven to 180 degrees C. Grease and flour a 20cm square cake tin.
2.
In a large bowl mix together the flour and sugar. Make a well in the centre and pour in the milk, oil, eggs, 2 tablespoons peanut butter and vanilla. Mix well and pour into prepared tin.
3.
Bake in the preheated oven for 30 to 35 minutes or until a toothpick inserted into the centre of the cake comes out clean. Allow to cool.
4.
To make the icing: In a large bowl combine 1 cup peanut butter and icing sugar. Beat in vanilla then milk to desired consistency. Spread on cake.