Preheat oven to 350 degrees. Line a 9- by 5- by 3-inch loaf pan with parchment paper and spray with baking spray (or grease it).
Pulse cranberry sauce in a food processor until finely chopped (do not puree); set aside.
Mix flour, baking powder and salt in a bowl. Beat together butter and the remaining 1 cup granulated sugar in the bowl of a mixer for about 5 minutes or until light and fluffy. Add eggs one at a time, beating well after each addition. Mix in the vanilla and orange zest. Reduce speed to low and add flour mixture and milk alternatively in batches, beginning and ending in flour. Mix until just incorporated.
Spread 1/2 of batter evenly in the prepared loaf pan. Spoon half of cranberry sauce evenly over batter, leaving a 1/2-inch border along sides. Cover with the rest of the batter. Sprinkle on the almond slivers and turbinado sugar (if you're using it).
Bake for 55 minutes or until a thin bladed knife inserted in the center comes out with just a few moist crumbs. (I checked my cake at about 50 minutes. Every oven is different). Let cool for 30 minutes. Slice and serve warm or at room temperature.