Preheat your oven to 350°F (175°C) and grease a 9x13 inch sheet pan.

In a medium bowl, whisk together all-purpose flour, baking powder, baking soda, salt, cinnamon, nutmeg, allspice, and ground ginger.

In a large bowl, mix sugar, vegetable oil, and vanilla extract until smooth, then add pumpkin puree and mix fully. Add eggs one at a time, mixing well.

Gradually fold the dry ingredients into the wet mixture until just incorporated.

Spread the batter in the prepared sheet pan and bake for 30-35 minutes.

Cool the cake in the pan for 15 minutes, then invert onto a serving plate and poke holes in the top.

Whisk together evaporated milk, sweetened condensed milk, and half-and-half, then pour over the cake.

Cover and refrigerate for at least 4 hours or overnight.

To make the spiced cream, whip heavy cream with sugar, cinnamon, and vanilla extract until peaks form.

Spread the spiced cream over the chilled cake, slice, and serve.