In a small bowl, mix brown sugar and hot water until dissolved. Chop roasted chestnuts into small pieces and add to sugar water. Add cinnamon and salt and mix. Set aside.

Whip Earth’s Balance and sugar until smooth. Add eggs, and beat for two to three minutes. Add vanilla and sour cream, and mix well, scraping down the sides of the bowl as needed.

In a glass measuring cup, combine flour, baking powder, baking soda and salt. Add to mixing bowl and whisk until incorporated.

Spray and flour a bundt pan with removable bottom (or a nine-inch springform) and pour half the batter into the pan. Sprinkle with sweetened chestnuts (and mini chocolate chips, if using), and then top with remaining batter.

In a small bowl, combine streusel ingredients and blend with a fork or your fingers until coarse crumbs are formed. Sprinkle over cake.

Bake for 45–50 minutes in an oven preheated to 350 degrees Fahrenheit, or until cake is set in the center. Allow to cool, and then remove sides and carefully transfer to cake plate.