Can use almonds instead of hazelnuts.

Preheat the oven to 350 degrees. Lightly oil a large baking pan and dust with flour. Shake off excess flour. Combine the flour, sugar, eggs, lemon rind, liqueur and rum in a mixing bowl and beat with a wooden spoon until thoroughly blended. Beat in the hazelnuts (or almonds) and bakingg powder. Using the hands, pick up half the dough [ick!] and shape it into a long sausage shape. Arrange it on the prepared baking pan, off center and not too close to the edge of the pan. Arrange the other half alongside but not too close. Both masses will spread as they bake. Place in the oven and bake for 1 hour. Remove from the pan and let cool for 20 minutes. Carefully and gently run a spatula or pancake turner under the 2 pastries. Let stand until almost at room temperature. Using a serrated bread knife cut each pastry into cross-wise slices, each about 3 cm think. Arrange these in one layer on a baking sheet and return to the oven to dry out, about 10 minutes. Let cool and store. These cookies are improved if a little anisette or other anise-flaovred liqueur is poured or brushed over them in advance of serving.