How to Make It
Melt chocolate in a small heavy saucepan over low heat; cool to room temperature.
Beat butter at medium speed with an electric mixer until creamy; gradually add sugar, and beat 5 to 7 minutes. Add chocolate and extracts, beating at low speed until blended.
Add 1/4 cup egg substitute; beat 5 minutes. Add remaining egg substitute, and beat 5 additional minutes.