Combine first 4 ingredients. Press into bottom of a buttered 9-inch deep-dish pieplate. Bake at 350° for 8 minutes or until lightly browned; cool.
Bring whipping cream to a simmer in a medium saucepan over medium heat. Remove from heat; add semisweet morsels, stirring until smooth. Spread mixture over crust; cover and freeze 30 minutes.
Melt 1/2 cup butter in saucepan. Remove from heat; add milk chocolate morsels, stirring until smooth. Add granulated sugar, stirring until smooth. Add eggs, 1 at a time, beating just until blended. Stir in flour just until combined.
Cut each chocolate piece into 4 pieces; fold into milk chocolate mixture. Pour mixture over chilled chocolate crust; sprinkle with pecan halves.
Bake at 350° for 45 minutes or until outer edge is set. Remove from oven; cool slightly on a wire rack. Serve warm.
*For testing purposes only, we used Nestlé Assorted Treasures.