1 lb. (500 g) pitted prunes
1 cup raisins (such as Thompson)
2 or 3 soda crackers (or melba toast)
1/2 cup walnuts
1/2 cup sugar
1 tsp. cinnamon
2 tsp. lemon juice
orange liqueur or orange juice, to taste
4 eggs, lightly beaten
3/4 cup vegetable oil
1/2 cup sugar
1 1/2 tsp. baking powder
1/2 tsp salt
3 cups (approximately) all-purpose flour
1 beaten egg (for glazing)
Process the prunes and raisins on the steel blade of the food processor until coarsely ground, about 12 to 15 seconds. Add the crackers and walnuts, then process with 3 or 4 quick on/offs, until finely chopped. Add the sugar, cinnamon and lemon juice and process just until combined. Add liqueur to taste, making the filling smooth enough to be able to spoon onto the dough.
Preheat oven to 350 F. Line baking sheet(s) with parchment paper.
In the large bowl of an electric mixer, beat eggs and oil together until light. Gradually add the sugar, baking powder, salt and 2 cups of the flour. Mix on low speed to combine, scraping down the sides of the bowl with a rubber spatula. Gradually add the last cup of flour, making a soft dough which is not sticky. If necessary, add a little extra flour.
Divide the dough into 4 sections and roll out each piece as thinly as possible on a well-floured surface into a large rectangle. Cut the dough into 3-inch rounds (or whatever size you like) with a round cookie cutter. Place a spoonful of filling in the centre of each circle. Shape into triangles by folding sides in towards the middle. Arrange the triangles on the prepared baking sheet(s), leaving 2 inches between each one. Lightly brush the tops and sides with beaten egg. Bake on the middle rack of the oven at 350 for 20 minutes, or until golden.