1.Preheat oven to 180°C/350°F. Grease a 20cm x 30cm (8-inch x 12-inch) slice pan; line base and long sides with baking paper, extending the paper 5cm (2 inches) over edges.
2.Beat eggs, sugar, syrup and oil in a small bowl with an electric mixer for 5 minutes or until thick and creamy. Transfer mixture to a large bowl; stir in pumpkin and nuts, then sifted dry ingredients. Spread mixture into pan.
3.Bake cake for 30 minutes or until a skewer inserted into the centre comes out clean. Stand cake in pan for 5 minutes before turning, top-side up, onto a wire rack to cool.
4.Meanwhile, make sugared pecans, then maple frosting.
5.To make sugared pecans; rinse nuts in a sieve under cold water until wet. Spread nuts, in a single layer, on a baking-paper-lined oven tray. Dust with sifted icing sugar. Roast in oven for 10 minutes or until browned lightly.
6.To make maple frosting; beat cream cheese and butter in a small bowl with an electric mixer for 3 minutes or until fluffy and smooth. Gradually beat in syrup and sifted icing sugar until smooth and combined.
7.Split cake in half. Place the bottom cake layer on a cake plate; spread with half the frosting. Finish with top cake layer and remaining frosting. Decorate with sugared pecans; dust with extra ground cinnamon.
You will need about half a small butternut pumpkin for the amount of grated pumpkin required. This cake can be made and frosted a day ahead;refrigerate. Stand at room temperature for at least 1 hour before serving. Sugared pecans can be made several days ahead; store in an airtight container at room temperature. Decorate cake with pecans just before serving.