Step 1

Butter an 8x8 baking pan. Line the pan with parchment paper, folding the paper over the edges, and lightly butter the parchment paper.

Step 2

Preheat the oven to 350°F.

Step 3

In a medium bowl, whisk together the sweet rice flour, brown sugar, granulated sugar, baking powder, cinnamon, nutmeg, ginger, cloves, and salt.

Step 4

In the bowl of a stand mixer fitted with a paddle attachment, or in a separate bowl with a hand mixer or hand whisk, mix together the pumpkin purée, coconut milk, eggs, butter, and vanilla until completely smooth.

Step 5

Slowly mix the dry ingredients into the wet ingredients, and beat vigorously until completely smooth.

Step 6

Fold in the black sesame seeds and pour the batter into the prepared pan.

Step 7

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.

Step 8

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. (It’s easiest to cut when cooled, using a knife buttered and dusted with sweet rice flour or potato starch).

Step 9

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).