175g butter, softened
1/4 cup icing sugar
few drops vanilla essence
1 1/2 cups standard plain flour
1/4 custard powder

Butter Filling:
50g butter, softened
1/2 cup icing sugar
2 tablespoons custard powder

Cream butter and icing sugar until light and fluffy. Add vanilla. Sift flour and custard powder together. Mix sifted ingredients into creamed mixture. Roll teaspoonsful of mixture into balls. Place on an oven tray. Flatten with a fork. Bake at 180C for 15-20 minutes. When cold, sandwich together in twos with Butter Filling.

Butter Filling:
Beat all ingredients together until well combined.

Makes about 20.