Preheat oven to 325 degrees F. In a medium saucepan, melt butter, xylitol, and heavy whipping cream over medium heat. Bring to a boil. Once boiling, remove from heat and add semi-sweet chocolate chips. Stir until fully melted.

Add egg and vanilla extract followed by the gluten-free all purpose flour and salt. Stir until batter is smooth. Pour batter into 9 inch pie pan. Bake for 18-23 minutes, or until toothpick comes out clean.

While brownies are baking, make the Coffee Pudding. Add cornstarch to a medium saucepan. Slowly add milk, whisking until cornstarch is fully dissolved. Add remaining milk, xylitol, butter, coffee, vanilla, and salt. Heat over medium-high heat until boiling. Heat for another 1-2 minutes, whisking continually, until thickened.

Once brownies have baked and have cooled for 5 minutes, add the coffee pudding in an even layer over the brownies.

After pie has been chilled thoroughly, make the whipped cream. Add heavy whipping cream, xylitol, and vanilla extract to a mixing bowl. Whisk until stiff peaks form and whipped cream is light and fluffy. Don't over mix!