Heat the oven to 350°F/180°C. Grease a 9-by-5-in/23-by-13-cm loaf pan with vegetable oil.
Combine the pumpkin purée, ground almonds, maple syrup, eggs, cinnamon, cloves, vanilla, salt, and baking soda together in a medium bowl, and stir well until a smooth batter forms. Stir in the chopped walnuts and chocolate chips (if using). Pour the batter into the prepared pan and scatter the sliced almonds evenly over the top.
Bake until the loaf is puffed and slightly browned and a tester inserted into the middle comes out clean, 35 to 40 minutes. Remove from the oven and cool in the pan for 15 minutes before turning out onto a wire rack to cool completely.
Store tightly wrapped in plastic wrap in the fridge for up to 1 week.
Recipe by Bakepedia at https://www.bakepedia.com/pumpkin-bread/