Pulse all-purpose flour, cake flour, 1 tbsp sugar, and 1/2 tsp salt in food processor until blended. Add 1/2 c butter, pulse until cut into smaller pieces. Ad shortening, pulse to cut up. Add 4 tbsp water; pulse until dough just begins to form, adding additional water as needed.
Shape dough into flat round. Cover and refrigerate 1 hour or up to 2 days.
Heat oven to 400. On lightly floured surface, roll dough into 13 inch roud; place in 10 inch tart pan with removable bottom. Trim overhan to 1/2 inch; fold overhang under. Firmly press sides of dough all around to extend 1/4 inch above rim of pan. Line crust with foil; fill with pie weights or dried beans.
Bake crust 15 min; remove foil and weights. Bake an addition 15 minutes or until golden brown. (If crust puffs during baking, poke with fork to break air pockets. Cool on wire rack.
Reduce oven temp to 300. Melt 2 tbsp butter in large nonstick skillet over medium heat. Stir in 2 tbsp syrup, cinnamon, nutmeg, and 1/8 tsp salt. Bring to a boil, stir in pecans until well coated. Cook 4 minutes or until pecans are deep golden brown and smell fragrant, stirring constantly. Spread on parchment paper-lined baking sheet; cool completely.
Meanwhile, whisk eggs in heavy medium saucepan until blended. Whisk in 1 cup syrup, 1/4 c sugar, and 1/8 tsp salt. Add 1/4 c butter, cook over medium heat 3-4 min or untill butter melts and sugar dissoves, whisking constantly. Remove from heat, stir in vanilla. Place tart pan on rimmed baking sheet. Pour hot filling into crust, sprinkle with pecans.
Bake at 300 for 25-35 min or just until full set with knife inserted in center comes out clean. Cool on baking sheet on wire rack 10 minute Remove tart from baking sheet, cool completely.