Preheat oven to 350 degrees F. Place hazelnuts in 9" by 9" metal baking pan. Bake 15 minutes, or until toasted. Wrap hot hazelnuts in clean cloth towel. With hands, roll hazelnuts back and forth to remove most of skins. Cool completely. Turn off oven.
In food processor with knife blade attached, or in blender, pulse nuts with 1/4 cup flour until nuts are finely ground.
In large bowl, with mixer at low speed, beat brown sugar and butter until blended. Increase speed to medium-high; beat until creamy, about 3 minutes, scraping bowl with rubber spatula.
Reduce speed to medium and beat in egg and vanilla until smooth, about 1 minute. Reduce speed to low. Add ground nut mixture, cinnamon, salt, baking powder, and remaining 1 cup flour; beat just until combined.
With floured hands, press two-thirds of dough into bottom and up side of 9-inch tart pan with removable bottom (1/4 inch below edge of pan). Wrap tart shell and remaining dough in plastic wrap and refrigerate 30 minutes, or until firm.
Preheat oven to 375 degrees F. Spread raspberry jam over bottom of tart shell to 1/4 inch from edge. Divide remaining dough into 10 equal pieces. On lightly floured surface, with floured hands, roll each piece into an 8 1/2-inch-long rope. Place 5 ropes, about 1 1/2 inches apart, over filling; do not seal ends. Make lattice top (if you're not sure how to do this, pick up a copy of the Good Housekeeping Great Baking cookbook -- available online and in stores now) with remaining 5 ropes. Trim ends of ropes even with edge of tart; press ends to seal. With any remaining trimmings, make rope for tart shell and press around inside edge of tart. Make decorative edge with fork, if desired.
Bake 35 to 40 minutes, until filling is hot and bubbly and crust is lightly browned. Cool on wire rack at least 1 hour. Sprinkle tart with confectioners' sugar, if desired. When cool, carefully remove side of pan.
Cranberry-Raspberry Linzer Tart: Prepare tart shell as above but make cranberry-raspberry filling: In 1-quart saucepan, heat 1 cup cranberries, picked over, 1/4 cup packed light brown sugar, 1/4 cup cranberry juice cocktail, and a pinch of salt to boiling over medium-high heat. Reduce heat to medium and cook, uncovered, stirring occasionally, 6 minutes, or until berries pop and mixture thickens slightly. Stir in 3/4 cup seedless raspberry jam. Cool before using. Fill tart shell, make lattice top, and bake as directed.
Each serving: About 205 calories, 3 g protein, 25 g carbohydrate, 10 g total fat (4 g saturated), 1 g fiber, 33 mg cholesterol, 140 mg sodium.
