Preheat oven to 325°, thoroughly grease a 8" or 9" spring form pan.
In the bowl of a stand mixer beat egg whites at high speed until beater leaves deep trails. Beat in 1/3 cup sugar 2 tablespoons at a time. Egg whites will be stiff and glossy (but not dry). Transfer to another bowl and set aside.
In mixer bowl (it is not necessary to wash the bowl) beat first 1/2 cup butter until creamy. Beat in remaining 1/3 cup sugar. Beat in 5 yolks, 1 at a time, at low speed.
Beat in chocolate and extracts. At low speed mix in almonds and Matzo Meal. Remove from mixer.
Stir in 1/4 of egg whites. Fold in the remaining egg whites gently. Pour batter into prepared pan.
Bake for 35-40 minutes or until torte starts to pull away from sides of pan.
Remove from oven and transfer to wire cooling rack. Cool for 10-15 minutes before loosening spring form pan, cool completely before icing.
While torte is cooling prepare the icing. Beat remaining 1/2 cup butter until creamy. Beat in powdered sugar one third at a time.
Beat in egg yolk (if using), melted chocolates, and rum. Scrape sides and bottom of mixer bowl well, beat again 1-2 minutes.
Frost torte, sprinkle with ground almonds for decoration if desired
Store in refrigerator, keeps well for 3-5 days. Freezes well, wrap in aluminum foil and defrost completely in foil before opening frozen torte. Best served at room temperature.