Rinse and clean berries, pat dry. Separate eggs. Whisk egg yolks with sugar and rum until fluffy, add butter. Beat egg whites with salt until stiff, fold into egg yolks. Combine flour with baking cream and sift over egg mixture, fold in carefully.
Line springform pan with parchment paper. Divide batter into two parts. Fold about 1/3 of berries into one half and spread in a pan, smooth. Spread with remaining batter and smooth. Bake in preheated oven at 180°C (approximately 350°F) for about 35-40 minutes. Remove from the oven and cool slightly. Loosen cake from the pan and transfer to a cake plate.
Whip cream with vanilla, cream stabilizer and powdered sugar until stiff and spread over cake. Arrange remaining berries on cake decoratively. Toast almonds in a dry pan and sprinkle over cake. Serve.