To prepare a Spanish flan recipe, first you need to prepare the filling. First, you'll need the following ingredients: 1 cup (240 ml) sugar, 1 tablespoon (25 g) flour, 2 tablespoons (50 mg) baking powder, and 1 teaspoon (0.5 tsp) salt. Mix the ingredients until they're well combined. Pour the mixture into an oiled and floured pie pan. Bake the pie for 35 to 40 minutes, or until the top is golden brown. Remove the pan from the oven and let it cool for 10 minutes before cutting into squares.