In a large mixing bowl, cream butter and shortening. With electric hand-held mixer on medium speed, gradually beat in the sugar. Beat in mascarpone cheese. Add flour, alternating with the eggs, beginning and ending with flour. Stir in vanilla. Pour batter into a greased and floured 10-inch tube pan or Bundt cake pan. Bake at 325° for about 1 hour and 15 minutes or until a wooden pick comes out clean when inserted in the center. Let cool in pan for 10 minutes, then remove to a rack to cool completely.
For Berry Salad:
In a large bowl, add all berries and sugar.
Mash berries slightly and add orange liqueur. Let sit for 30 minutes until ready to serve.
Slice pound cake and top with macerated berries and whipped cream. Garnish with mint.