Preheat your kitchen oven to 350 degrees Fahrenheit so it is hot and ready. Line your loaf pan with parchment paper, leaving a small overhang on the sides for easy lifting.

Combine three tablespoons of granulated sugar and one tablespoon of ground cinnamon in a small bowl. Stir them together with a small spoon until the mixture is uniform, then set it aside.

Whisk the all-purpose flour, baking soda, pumpkin pie spice, and salt together in a large mixing bowl. Make sure there are no lumps in the flour so your bread rises evenly in the oven.

In a separate bowl, whisk the pumpkin puree, melted butter, eggs, brown sugar, and remaining granulated sugar. Mix vigorously until the liquid mixture is completely smooth, shiny, and well combined.

Gently pour the wet ingredients into the dry flour mixture using a flexible rubber spatula. Fold them together slowly just until the flour disappears, being very careful not to overmix the thick batter.

Spread half of your golden pumpkin batter evenly into the bottom of the prepared loaf pan. Sprinkle the cinnamon-sugar mixture over it, then spoon the remaining batter carefully on top.

Insert a clean butter knife into the filled pan and gently drag it in a zigzag pattern. This simple motion creates that gorgeous, professional-looking cinnamon swirl pattern throughout the bread.

Bake in your preheated oven for about sixty minutes until a toothpick inserted in the center comes out clean. Let the warm loaf cool inside the pan for ten minutes before slicing.