Clementine Cake

3 medium clementines (approx. 12 ounces)
1 1/2 cups white sugar
3/4 cup softened butter
3 eggs
2 cups white flour
2 teaspoons baking powder
1/2 teaspoon salt
ICING
2 teaspoons clementine zest
2 tablespoons clementine juice (from 1 clementine)
2 tablespoons softened butter
1 1/3 cups icing sugar
1 tablespoon orange liqueur (optional)

Wash and remove stems from clementines, cut into quarters, process clementines with sugar in food processor until smooth.
Add butter, then eggs; process until smooth Add flour,baking powder, process until combined.
Spoon into greased 8-cup bundt pan.
Bake at 350 degrees approximately 50 minutes, until golden (depends on your oven). Cool on rack 10 minutes, then remove cake from pan and leave on the rack until cold.
Icing:.
Grate rind and squeeze juice from the clementine.
Measure 2 tsp rind and 2 tblsp juice into a bowl, add butter, icing sugar and liqueur.
Mix until icing is smooth.
Drizzle the icing over the cooled cake.