Preheat to 400°F.

Combine flour, brown sugar, baking powder, baking soda, and salt in bowl of food processor. Add 6 tablespoons butter and process using pulse until butter pieces are pea sized. Put mixture into mixing bowl.

Mix in pecans.

Whisk buttermilk, egg yolks and extract in medium bowl. Add to flour mixture. Toss with fork until dough comes together in moist clumps. Gather dough into a ball and press out on lightly floured surface and shape into an 8-inch round; cut into 6-8 pieces and round off edges to form circular piece of dough.

Arrange scones 1 inch apart on ungreased baking sheet. Bake until tester inserted into center comes out clean, about 16 minutes.

For the Glaze

Whisk remaining 1/2 cup brown sugar, 4 tablespoons butter, half and half, maple extract and molasses in heavy small saucepan over low heat until sugar dissolves. Remove pan from heat. Whisk in powdered sugar. Spread glaze over warm scones. Let stand until glaze sets, approximately 30 minutes. (I was bad...I know I had one before 15 minutes was up!)