Preheat oven to 350F and grease and line a 9-inch cake pan. Set aside.
In bowl, stir together yogurt, honey and vanilla paste. Cover and refrigerate until ready to use.
In a large bowl, cream butter in a stand mixer or with a hand mixer. Add sugar; beat until light and fluffy, about 3 minutes. Beat in orange zest, juice and cardamom until well blended. Add one egg at a time, beating well after each egg. Mix in yogurt.
Add flour and stir just to combine. Spread batter into prepared pan and bake for 50-55 minutes or until a skewer inserted into the centre comes out clean.
Let cool on rack for 5 minutes before inverting onto the cooling rack, remove pan; let cool completely.
Transfer to cake plate. Spread yogurt frosting on top and sprinkle with pistachios and pomegranate seeds. Serve immediately or refrigerate until ready to use.