Preheat oven to 350 degrees F. Grease a 10-inch cake pan.

Make the apple cardamom cake batter. Whisk together vegetable oil with 2 large eggs, Greek yogurt, and vanilla until smooth.

In a separate bowl, combine the flour with 2 cups sugar, 2 teaspoon cinnamon, baking powder, baking soda, salt, and cardamom. Add the wet ingredients to the flour mixture, stirring just until combined. Fold in the chopped apples and pour the batter into the prepared cake pan.

Make the cinnamon-sugar streusel. Combine ¼ cup sugar with 1 teaspoon cinnamon, ½ teaspoon cardamom, and 1 tablespoon melted butter until well combined. Sprinkle the streusel on top of the cake.

Bake the cake for 40-45 minutes or until a toothpick inserted in the center comes out clean. Remove the cake from the oven and let cool completely on a wire rack.

Meanwhile, make the pistachio cream. In a food processor, grind the pistachios until smooth, about 7-8 minutes. Add the powdered sugar and process until combined. Add 2 tablespoon water and process and until smooth and thick, another 1-2 minutes. Add 1 cup heavy cream and process until creamy and thick, about 3 minutes. Chill the pistachio cream until ready to serve.