For the pumpkin spice cake, preheat the oven to 180 °C. Grease a rectangular shallow baking pan (20 x 30 cm), line bottom and long sides with baking paper, leaving 5 cm overhang.
Beat the eggs, sugar and oil with a hand mixer for about 5 minutes until creamy. Stir in the pumpkin and nuts, then the sifted other ingredients (except for 1/4 tsp cinnamon for dusting). Pour the batter into the pan.
Bake the batter for 30 minutes (do a proofing). Let the cake rest in the pan for 5 minutes, then transfer to a cooling rack to cool.
Meanwhile, prepare the sugared pecans and maple syrup cream.
For the sugared pecans, rinse the nuts in a colander under cold water. Spread on a baking sheet lined with parchment paper and dust with confectioners’ sugar. Roast lightly in the oven for about 10 minutes.
For the maple syrup cream, beat the cream cheese and butter with a hand mixer for about 3 minutes until fluffy. Gradually stir in syrup and sifted powdered sugar.
Cut the pumpkin spice cake in half crosswise. Spread the bottom layer with half of the cream. Finish with the top layer and the remaining cream. Garnish with the sugared pecans and dust with the remaining cinnamon.