Preheat the oven to 350 degrees. Coat an 8 x 8 baking dish with cooking spray.
Combine the flour, baking powder, cinnamon, baking soda, ginger, allspice, cardamom, and salt in a bowl; mix well.
In a separate large bowl, whisk together the melted butter and white sugar until well combined.
Add the eggs and whisk.
Add in the fresh clementine juice and zest, then whisk until well combined.
Gradually add the flour mixture to the wet ingredients and mix until incorporated.
Pour the cake batter into the prepared baking pan and bake for 30-35 minutes, or until a tester inserted in the center comes out with very little crumb.
Remove from the oven and let the cake cool completely on a wire cooling rack.
When ready to serve, sprinkle the top with powdered sugar, then slice.
Serve with whipped cream on top, if desired. Enjoy.