Preheat oven to 425 degrees. Combine the yeast, half-and-half and 1/2 teaspoon evaporated cane juice in the bowl of a stand mixer, mix well and let stand until bubbles form on the surface. Add the flour, salt, eggs and beat with the paddle for 3 minutes at medium speed. Add 5 ounces of butter and mix until just incorporated. Cover the bowl with plastic and let rise in a warm, draft-free space until doubled in bulk – about 1 to 1 1/2 hours.

Punch down the dough gently. Butter a cookie sheet and spread the dough onto it, making a 12 x 15 inch rectangle about 1/4 inch thick. Brush the top with the melted butter and sprinkle with the 1/4 cup of cane juice. Place in the center rack of the oven and bake for 20 minutes until evenly golden brown.

Place the cherries in a non-reactive bowl and pour the boiling water and 1 cup port over them. Cover the bowl with plastic and let steep for 2 hours. Drain the juice and pour into a sauce pan. Add the potato starch water mixture and bring to a boil. Cook for 2 minutes. Remove from the heat and cool to room temperature and add the remaining 1/2 cup port.

Whip the cream to soft peaks then fold in the sour cream.

Cut the brioche into 8 portions, place on dessert plates and top with the poached cherries and crème.