Preheat oven to 350 degrees F (175 degrees C). Lightly oil a 10 inch non-stick Bundt pan.
In a large bowl, combine cake mix, eggs, pudding mix, 1/2 cup of cold water, oil, 1/2 cup amaretto and 1/4 teaspoon almond extract. Blend well for approximately 3 minutes.
Pour batter into prepared 10 inch Bundt pan. Bake at 350 degrees F (175 degrees C) for 45 minutes to an hour, or until a toothpick inserted into the center of the cake comes out clean.
Remove cake from oven, and use an ice pick or skewer to make as many holes as possible into the cake. Apply glaze while cake is still warm. Slowly and patiently drizzle glaze over cake, including the edges and center of Bundt pan. Allow cake to cool in the pan for at least 2 hours.
To make the glaze: Combine butter, sugar, 1/4 cup water, and 1/2 cup amaretto in a saucepan. Bring to a boil, and continue to boil for 10 minutes, stirring constantly.
Topping: Lightly toast slivered almonds in the oven. This will take 5 to 10 minutes. Stir frequently and be careful not to burn. Heat 1/4 cup of the prepared frosting in the microwave for 10 seconds, to soften. Place the cake on serving dish and use a spoon to drizzle the softened frosting over the cake. Scatter toasted almonds over cake before frosting cools.