Preheat the oven to 325 degrees Fahrenheit and grease two 8.5 x 4.5 inch loaf pans.
In a mixing bowl, combine the flour, pumpkin pie spice, baking soda, cayenne pepper powder, baking powder, and kosher salt. Mix thoroughly.
In a mixer, add the unsalted butter and mix the butter until smooth and creamy.
Add the sugar to the butter and beat the sugar/butter mix for approximately 3 minutes.
Add the eggs one at a time, beating each separately into the butter/sugar mix.
Add the pumpkin puree and vanilla extract, and mix slowly until combined. Then slowly mix in the spiced flour until fully combined in the batter.
Pour the batter into the greased loaf pans, then place the loaf pans in the oven. Bake the spicy pumpkin bread for 65 to 70 minutes, until cooked through.
Remove the loaf pans and place them on a rack to cool for 15 to 20 minutes. Once cool, remove the bread from the loaf pans. Slice and serve.