Preheat oven to 350F – place oven racks at lowest and middle positions.
Line bottom and sides of torte pan with foil; grease foil.
Melt butter and chocolate in double boiler over low/med heat; remove from heat and cool.
In medium bowl, beat egg whites until stiff, about two minutes.
In another bowl, beat egg yolks and sugar until thick and pale; about one minute.
Blend chocolate mixture into yolks and fold in almonds and optional rum.
Fold egg whites into chocolate mixture, 1/3 at a time, stirring so that no streaks of white remain.
Scrape into prepared pan.
To help ensure a moist torte, place an 8" pan with 1" water on the bottom rack of the oven.
Bake torte on centre rack for 45-50 minutes or until sides begin to pull away from pan and top is set in centre.
Cover torte loosely with foil for the last 20 minutes of baking.
Cool on wire rack for 10 minutes and then carefully remove sides of pan; invert torte onto a serving plate and cool completely.
