Preheat the oven to 350°F. Line an 8-inch cake pan with parchment paper and spray the sides with a baking spray.

Place the granulated sugar into a large mixing bowl and zest in the orange. Use your fingers to blend the zest and sugar together.

Add in the eggs, sour cream, melted butter, orange juice, and rosewater/extract. Whisk until 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 until well combined.

Fold in the finely diced pistachios.

Pour the cake batter into the prepared pan. Spread the batter evenly. Bake at 350°F for 33 to 35 minutes, until a toothpick inserted comes out clean.

Allow the cake to cool in the pan for about 5 minutes, then remove onto a wire rack to cool completely.

Prepare the glaze by mixing powdered sugar, orange zest, rosewater/extract, and heavy cream until thick.

Allow the cake to cool to room temperature before adding the glaze. Pour the rosewater glaze onto the center of the cake and gently nudge it to the edges.

Garnish the top of the cake with diced pistachios, rose petals, and/or rose buds.