Pumpkin & caramel cake

Name: Pumpkin & caramel cake
Prep time: 45 min
Cook time: 30 min
Total time: 1 h 15 min
Cuisine: American
Ingredients: 80ml vegetable oil plus extra for greasing; 450g pack vanilla or white cake mix (or make your own cake mix, see tip below); ½ x 425g can pumpkin purée; 125ml full-fat milk; 4 large eggs; 1 tsp pumpkin pie spice (available from uk.iherb.com, or mix it yourself by combining 1/2 tsp ground cinnamon, 1/4 tsp ground ginger, 1/4 tsp nutmeg and a pinch of ground cloves); 4 tbsp dulce de leche from a jar; 225g full-fat cream cheese; 125g icing sugar sifted; 1 tsp pumpkin pie spice; 440ml double cream; 70g pecans toasted and roughly chopped