• Preheat the oven to 200°C (400°F). Line a 12-hole muffin tin with muffin liners.
• In a large bowl, combine flour, baking powder, baking soda, spices and salt.
• In a separate large mixing bowl, combine pumpkin puree, vegetable oil, sourdough discard, both types of sugar, milk, and eggs. Using an electric handheld mixer, beat the mixture for 1-2 minutes until well combined and increased in volume.
• Add the flour mixture to the wet ingredients and, using a rubber spatula, gently fold everything together. Avoid overmixing.

Make Streusel Topping

• In a medium bowl, mix the sugar, flour and a pinch of salt. Add the cubed butter and rub with your fingertips until the mixture resembles coarse breadcrumbs. If using pumpkin seeds, stir them in at the end.

Assemble and Bake

• Spoon the sourdough pumpkin muffin batter into the muffin cases, filling them almost all the way to the top.
• Spoon plenty of streusel mixture over the top of each muffin.
• Bake the muffins for 22-28 minutes until a wooden skewer inserted into the centre of the muffin comes out clean (I bake regular muffins for 22 minutes, but if I make 8 tall muffins in tulip cakes (as photograpghed), it takes about 27-28 minutes).
• Remove the muffins from the tin and let them cool down to room temperature.