01 - Preheat oven to 350°F. Grease and line a 9x5-inch loaf pan with parchment paper.
02 - In a large bowl, whisk together flour, sugar, cinnamon, baking powder, baking soda, and salt until evenly combined.
03 - In a separate bowl, beat eggs, add vegetable oil, buttermilk or prepared milk mixture, and vanilla extract. Stir until smooth.
04 - Pour wet ingredients into the dry ingredient bowl. Mix gently until just incorporated; avoid overmixing.
05 - Fold in cranberries and nuts, if using, ensuring even distribution.
06 - Transfer batter into prepared loaf pan. Sprinkle top with coarse sugar if desired.
07 - Bake at 350°F for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean.
08 - Let loaf cool in the pan for 10 minutes, then move to a wire rack to finish cooling before slicing.