Prepare crust: With mixer at low speed, beat butter and sugar until light and fluffy; add egg until blended. Add flour; beat until blended. Grease 9-inch tart pan with removable bottom. Press dough into bottom and up sides of pan. Prick crust with fork. Spread bottom with jam. Refrigerate.
Preheat oven to 350°F. Prepare filling: With mixer at low speed, beat almond paste, sugar and egg. Add butter and almond extract; beat until just blended. Add flour and baking powder; beat well. Spoon mixture over jam in crust.
Arrange pear halves, cut-side down on mixture in crust. Bake 50 minutes until filling is set. Cool completely.