• Preheat the oven to 350°F. Line an 8-inch cake pan with parchment paper and spray the sides with a baking spray. A 9-inch pan will also work but will result in a thinner cake and will require less baking time.

Preparing the Cake Batter:

• Place the granulated sugar into a large mixing bowl and zest in the orange. Use your fingers to blend the zest and sugar together, releasing the orange oils.
• Next, add in the eggs, sour cream, melted butter, orange juice, and rosewater/extract. Whisk or beat for a few minutes until the eggs are well-beaten.
• In a separate bowl, combine the dry ingredients: all-purpose flour, almond flour, baking powder, baking soda, salt, and ground cardamom.
• Sift the dry ingredients into the wet ingredients, then mix just until well combined.
• Last, fold in the finely diced pistachios.

Baking Instructions:

• Pour the cake batter into the prepared pan. Use a spoon to spread the batter evenly to the edges, ensuring there are no air pockets.
• Bake at 350°F for 33 to 35 minutes, until a toothpick inserted into the center comes out clean.
• Allow the cake to cool in the pan for about 5 minutes, then remove onto a wire rack to cool completely.

Making the Glaze:

• Next, prepare the glaze. Place the powdered sugar into a medium mixing bowl. Add the orange zest, rosewater/extract, and a few tablespoons of heavy cream.
• Whisk the ingredients together to form a thick glaze. Add more cream as needed to thin the glaze; it needs to be on the thicker side but pour freely.
• Allow the cake to cool to room temperature before adding the glaze. If the cake is too warm, the glaze will melt and pour off the sides.

Garnishing the Cake:

• Pour the rosewater glaze onto the center of the cake, then use an offset spatula to gently nudge it to the edges and down the sides.
• Garnish the top of the cake with diced pistachios, rose petals, and/or rose buds. Store the cake at room temperature for up to 3 days, or cover and store in the fridge for 1 week.