In a medium bowl, combine all-purpose flour, ground cinnamon, granulated sugar, brown sugar, and a pinch of salt. Stir until well mixed, then drizzle in the melted butter. Use your fingers to mix until it forms small clumps and resembles wet sand. Set aside your crumb topping.

Preheat your oven to 350°F (175°C). Grease a 9”x5” Pullman loaf pan generously with butter.

In a large bowl, whisk together the all-purpose flour, salt, baking powder, baking soda, and pumpkin pie spice until well combined.

In another bowl, mix melted butter with brown sugar until smooth. Add an egg, pure vanilla extract, sourdough discard, and pumpkin puree. Whisk thoroughly to combine.

Pour the wet mixture into the dry ingredients, gently stir with a spatula until just combined.

Transfer the batter into the prepared loaf pan and smooth the top with a spatula. Evenly sprinkle your prepared crumb topping over the batter.

Place the loaf pan in the preheated oven and bake for approximately 60 minutes. Check for doneness with a toothpick.

Remove the pan from the oven and allow the bread to cool in the pan for 10-15 minutes. Transfer it to a wire rack to cool completely before slicing.