Heat oven to 350° and coat an 8-inch square pan with cooking spray, set aside.
Whisk together the flour, xanthan gum (if using), baking powder, and salt in a small bowl.
Stir together the sugar and pumpkin in a medium bowl until well combined.
Beat in the whole egg and egg white.
In a separate small bowl, mix together the vanilla and espresso powder until the powder is dissolved and then add to the sugar/ pumpkin mixture.
Melt coconut oil in a medium saucepan over low heat slowly stir in cocoa powder, stirring with a fork until the chocolate mixture resembles a smooth sauce.
Combine the flour mixture with the pumpkin mixture until no trace of the flour remains.
Stir in the chocolate mixture and mix until the batter is dark brown.
Carefully fold in the raspberries.
Spoon the batter into the baking pan and smooth the top with a spatula coated with cooking spray.
Bake until a wooden pick inserted in the center of the brownies comes out clean, 25 to 30 minutes.
Cool and cut into 12 brownies.