-
1
Preheat oven to 350F and butter a 9-inch springform pan.
-
2
In a small saucepan melt butter and stir in cocoa powder.
-
3
Remove pan from heat and add brown sugar, stirring until dissolved.
-
4
Stir in flour, walnuts, egg, and vanilla and spread batter evenly in springform pan.
-
5
Bake base in middle of oven 10 minutes, or just until firm, and transfer to a rack to cool.
-
6
Arrange walnuts in one layer on top of base.
-
7
In a small heavy saucepan combine butter, brown sugar, and honey and cook over moderate heat, stirring occasionally, 8 to 10 minutes, or until a candy thermometer registers 280F.
-
8
Remove pan from heat and add cream, vanilla, and lemon juice, stirring until smooth.
-
9
Cool mixture to room temperature and pour over walnuts, spreading evenly.
-
10
In a saucepan bring cream just to a boil.
-
11
Finely chop chocolate.
-
12
Put chocolate in a metal bowl and pour hot cream over it, stirring until smooth.
-
13
Cool ganache to room temperature and beat with an electric mixer until it just holds soft peaks (do not overbeat or it will become grainy).
-
14
Spread ganache evenly over filling.
-
15
Chill cake, covered, at least 4 hours and up to 1 day.
-
16
Run a thin knife around edge of cake and remove side of pan.
-
17
With a large spatula transfer cake to a plate and let stand at room temperature 30 minutes before serving.
