Preheat oven to 350 degrees Fahrenheit.
Grease a 8.5" x 4.5" loaf pan and line with parchment paper, with parchment sticking out of the top of both sides of the loaf pan like handles.
Combine all ingredients, except cassava flour, baking powder, and pumpkin seeds, in the bowl of a stand mixer or a large mixing bowl. Or use your hand mixer.
Use stand mixer fitted with paddle attachment or hand mixer to mix until smooth.
Add in cassava flour and baking powder and mix again until totally incorporated and smooth.
Transfer the batter to the prepared loaf pan.
Top with soaked and dried pumpkin seeds, if using.
Bake for 45 to 55 minutes, or until a toothpick inserted comes out clean.
Leave in the pan to cool for 10 to 15 minutes, then use the parchment "handles" to lift the loaf out of the pan.
Place on a cooling rack to finish cooling. Or serve warm.
Store leftovers tightly wrapped or in an airtight container in the fridge.