Preheat your oven to 180°C (350°F). Line a muffin tin with paper liners or grease it well.
In a large mixing bowl, whisk together the flour, baking powder, and salt until evenly combined. This ensures your leavening is evenly distributed.
Zest the orange directly into a separate bowl, then juice it to get about 1/4 cup of fresh orange juice. The zest adds bright aroma, while the juice adds moisture and tang.
In a medium bowl, combine the melted butter, granulated sugar, orange juice, and eggs. Whisk everything together until the mixture is smooth, slightly frothy, and fragrant with citrus.
Pour the wet mixture into the bowl with the dry ingredients. Gently fold with a spatula just until the batter is combined—be careful not to overmix, as this keeps the muffins tender.
Fold in the chopped cranberries evenly into the batter, distributing their tart color and flavor throughout.
Using a muffin scoop or large spoon, portion the batter into the prepared muffin cups, filling each about two-thirds full to allow room for rising.
If desired, sprinkle oats or sliced almonds on top of each muffin for added crunch and visual appeal.
Bake in the preheated oven for 20-25 minutes, or until the tops are golden and a toothpick inserted into the center comes out clean. The kitchen will smell bright and citrusy as they bake.
Remove the muffins from the oven and let them cool in the tin for about 10 minutes. Then transfer them to a wire rack to cool completely or enjoy warm.
Serve these muffins with a pat of butter or a drizzle of honey, and enjoy their moist, fluffy crumb and bright citrus flavor.
