Prepare the pan 8x8, layer it with parchment paper. Preheat the oven 175 celcius
In a medium bowl, whisk together the sweet rice flour, brown sugar, granulated sugar, baking powder, cinnamon, nutmeg, ginger, cloves, and salt.
In a separate bowl with a hand mixer or hand whisk, mix together the pumpkin pure, coconut milk, eggs, butter, and vanilla until completely smooth.
Slowly mix the dry ingredients into the wet ingredients, and beat vigorously until completely smooth.
Fold in the black sesame seeds and pour the batter into the prepared pan.
Bake in on the middle rack of the oven for 75-80 minutes, until the top has developed a slight crust and the mochi is completely set and bounces back when touched.
Let cool in the pan for 10 minutes before using the parchment paper to transfer to a wire rack to cool completely, at least 25 minutes. Cut into 16 squares. (Its easiest to cut when cooled, using a knife buttered and dusted with sweet rice flour or potato starch).
Dust the top of the mochi squares with powdered sugar. Store for up to 3 days in an airtight container at room temperature (the longer they sit, the softer the top crust will get and the powdered sugar might need to be reapplied before serving).
