Preheat the oven to 350 degrees F. Butter and flour a 10 or 12-inch fluted bundt pan.
In a large mixing bowl, combine the cake mix, instant pudding powder, eggs, 7up soda, vegetable oil, and almond extract (if using); mix with an electric mixer or whisk vigorously for 2 minutes until well blended. Gently fold in the chopped pistachios.
Pour the batter evenly into the prepared bundt pan.
Bake for about 40 minutes or until a toothpick inserted in the center comes out clean. Once baked, remove from the oven and let cool for 10 minutes. Use a dull knife to gently loosen the edges. Allow the cake to cool completely.
Carefully turn the cake out onto a wire rack or plate and dust with powdered sugar.
Slice and enjoy!