• Preheat the oven to 350°F (180°C).
• Grease a 10 to 12-cup bundt cake pan (26cm) with 2 tablespoons shortening, making sure every nook, cranny and angle is covered. Dust with flour, shaking off excess. Reserve.

For the cake:

• In a large bowl with an electric mixer (or the bowl of a stand mixer) beat 1 ½ cups unsalted butter until creamy.
• Gradually add 2 cups white sugar and beat until creamy and light in color, about 3 minutes.
• Add 6 eggs, one at a time, beating well after each addition. 
• Add ½ teaspoon vanilla extract, 1 ½ teaspoons almond extract, 1 teaspoon orange zest and ½ cup ground almonds (or almond flour) and mix without beating much. 
• Sift 3 cups all-purpose flour with ½ teaspoon baking powder and ½ teaspoon baking soda and ½ teaspoon salt. Add them in 3 parts to the butter mixture, alternating with 1 cup sour cream in 2 parts. That means you begin and end with flour. 
• Beat until well mixed and smooth but don’t overbeat at this point. 
• Pour the batter into the cold pan and bake for about 1 hour or until a toothpick inserted comes out clean. 
• Let cool on wire rack for 10 minutes, shake the pan to make sure the cake is loose and unmold carefully. 
• Let cool completely on the wire rack before glazing.

For the glaze:

• In a small bowl mix 1 ½ cups powdered sugar with 2 tablespoons milk and ⅛ teaspoon almond extract until very creamy. If needed add more milk until you have the desired consistency. 
• Pour over cold cake and sprinkle with 2 tablespoons sliced almonds before it sets.