Brownie Biscotti

Yield:	1 Servings
Categories:

1/3	c	Butter--no substitutes
2/3	c	Sugar
2	ts	Baking powder
2		Eggs
1	ts	Vanilla
1/3	c	Unsweetened cocoa powder
1 3/4	c	All-purpose flour
1/2	c	Miniature semisweet chocolate pieces
1/4	c	Finely chopped walnuts
1		Beaten egg yolk
1	tb	Milk or water