Heat oven to 350 F. Grease and line an 8 1/2 x 4 1/2 inch loaf pan with parchment paper. Place pecans in the oven on a baking sheet and toast for 6 to 8 minutes until fragrant. Remove and roughly chop, then set aside.
Place sugar in the bowl of an electric mixer or a large mixing bowl and zest the orange peel into the sugar. Rub with your fingertips to break up the orange zest and spread the orange oil among the sugar granules.
Cut oranges in half and juice them into a liquid measuring cup. Spoon in sour cream until the juice reaches the 1 cup line. Using the paddle attachment on a stand mixer, or a hand mixer, beat the melted butter, egg, and vanilla extract into the sugar on medium speed. Add in the orange juice and sour cream and beat until just combined.
Sift the dry ingredients (flour, baking powder, baking soda, and salt) into the butter mixture. Beat on low speed to combine flour mixture with wet ingredients.
Stir in the cranberries and pecans until just combined.
Scrape the cake batter into the prepared loaf pan.
Bake in preheated oven 60 to 70 minutes, rotating at the 30 minute mark, until a cake tester inserted into the center of the cake comes out clean and the sides of the cake begin to pull away from the pan. If the top of your cake begins to get too dark but the center of the cake is still wet, you can tent the top of the cake with aluminum foil.
Remove to cooling rack and cool to room temperature.