Preheat oven to 190ºC. Warm the oil and butter in a small saucepan until the butter melts. Use a little of the mixture to grease 8 individual tart pans 7 cm in diameter.
Whisk the eggs, evaporated milk, brown sugar, coconut, orange zest and juice and the spices in a large bowl until well combined. Stir in the puréed pumpkin.
Cut filo pastry into even squares, 8 from each sheet (32 in total). Layer 4 squares into each of the 8 pans, brushing each layer with oil and butter mixture. To create a petal effect, layer squares at angles to one another. Spoon pumpkin mixture into the centre of each tartlet.
Bake tartlets until filling is set, 20 to 25 minutes. Transfer the pans to a wire rack; cool tartlets briefly. Just before serving, top with blackberries and a light dusting of icing sugar.