Preheat oven to 400 degrees F. Prepare a baking sheet by lining with a silicon baking sheet or parchment paper.
In a medium bowl, combine gluten free flour, guar gum, brown sugar, baking powder and salt. Using a fork or pastry blender, add butter to the flour mixture until it forms small crumbles. Add heavy cream, vanilla and pecans and combine until the mixture forms into a lump, using your hands if necessary.
Remove dough from bowl and shape into an 8 in. round circle, approx. 1 ½ inches tall. Cut the circle in half, and keep cutting until you have 8 even triangles. Transfer each piece to a baking sheet. Bake for 9-11 minutes. Remove from oven and allow to cool.
Once the scones have cooled slightly, mix the powdered sugar, maple syrup, vanilla, butter in a small bowl until smooth. Add 1 Tbs of heavy cream at a time to ensure your glaze will not be too thin. Drizzle over scones, top with pecans if desired and serve.