Preheat the oven to 350°F and line a 9x9 baking pan with parchment paper.
Mix melted butter with sugar using a whisk.
Add in the eggs and mix well.
Add in the clementine juice and whisk until well incorporated.
In another bowl, mix all purpose flour, ground ginger, cinnamon, allspice, cardamom, salt, clementine zest, baking powder and baking soda.
Add the dry ingredients to the wet ingredients and mix until incorporated.
Pour the cake batter into the baking pan and bake in the oven for 30 to 35 minutes until a toothpick inserted in the middle comes out cleans or with very little crumb.
Let the cake cool completely, then slice it and serve with whipped cream and clementine.