Step 1

In food processor, place flour blend, 1 tablespoon sugar, the xanthan gum and 1/2 teaspoon salt. Cover; process until combined. Add butter; pulse 3 to 5 times or until mixture looks like coarse crumbs.

Step 2

In 1-cup measuring cup, beat 1 egg yolk, vinegar and 3 tablespoons water with fork. With food processor running, quickly pour egg mixture through feed tube, and process a few seconds until dough begins to come together. (Add additional water if necessary.) Remove dough; shape into flattened disk. Cover with plastic wrap; set aside.

Step 3

Heat oven to 425°F. To make Filling, in medium bowl, beat eggs lightly with whisk or hand beater. Beat in remaining filling ingredients until well blended; set aside.

Step 4

Remove plastic wrap from dough. On 12-inch square of cooking parchment paper lightly sprinkled with flour blend, roll dough into 11-inch circle. Carefully center ungreased 9-inch pie plate over circle. Turn crust and pie plate over to place crust into pie plate. Remove paper. Ease crust into pan, repairing any tears with wet fingers. Trim overhanging edge of pastry 1 inch from rim of pie plate. Fold and roll pastry under, even with plate; flute as desired. Pour filling into crust.

Step 5

Bake 15 minutes. Reduce oven temperature to 350°F. Bake about 45 minutes longer or until knife inserted in center comes out clean. Cool 30 minutes. Refrigerate about 4 hours or until chilled. Cover and refrigerate any remaining pie.