Preheat oven to 350 degrees.
Place almonds on a rimmed cookie sheet in a single layer and bake for 1 to 2 minutes, just until golden. They toast very quickly, so watch them carefully to avoid burning!
Bake cake batter according to package directions for two 9-inch round layers; let cool. Remove from pans.
In a medium-size bowl, combine ricotta cheese, chocolate chips, ¼ cup granulated sugar, vanilla, and cinnamon; mix well, then cover and chill. In a small bowl, combine rum, water, and remaining 2 tablespoons granulated sugar; mix and set aside. Place 1 cake layer on a serving platter and drizzle with rum mixture until liquid is completely absorbed. Cover with ricotta cheese mixture and top with second cake layer.
In a medium-sized bowl, with an electric beater on high speed, beat heavy cream and confectioners’ sugar 5 to 6 minutes, until stiff peaks form. Frost top and sides of cake with whipped cream and sprinkle top and sides with toasted almonds. Cover loosely and chill at least 2 hours before serving.