Heat oven to 350 F.
In double boiler, melt chocolate and butter.
When melted, place in large bowl and whisk in cocoa powder until smooth. Add sugar and mix.
Combine eggs and vanilla; gently mix with fork or whisk to break up eggs. Add eggs and vanilla to batter.
Sift together flour, salt and baking powder. Fold in flour until just combined.
Spray Fillables 8 Cup Cake Cone Pan with nonstick cooking spray. Fill bottom pan with batter to line in middle of pan then place insert on top and snap together.
Place on middle of rack in oven and bake 15-18 minutes. Allow to cool before removing from pan.
Add fillings inside cone, top with Vanilla Frosting or ice cream, and serve.