Set your oven to 350°F (175°C). Lightly grease your 9x9-inch baking pan and dust with flour to prevent sticking, or line it with parchment paper for easy removal.
In a medium bowl, sift together the all-purpose flour, baking powder, salt, ground cinnamon, nutmeg, and ginger. This ensures an even distribution of spices and leavening agents.
In a separate large bowl, whisk together granulated sugar, vegetable oil, whole milk, eggs, pumpkin puree, and vanilla extract until smooth and well blended.
Gradually add the dry ingredients to the wet mixture, folding gently with a spatula until just combined. Avoid overmixing to keep the cake tender and light.
Pour the batter into your prepared pan, smoothing the top with a spatula. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. Remove from oven and let cool completely on a wire rack.
In a bowl, whisk together the sweetened condensed milk, evaporated milk, and heavy cream until fully combined.
Once cooled, use a fork or skewer to poke holes all over the cake surface. Slowly pour the milk mixture evenly across the cake, allowing it to soak in. Cover and refrigerate for at least 4 hours, preferably overnight, to let the flavors meld and the cake absorb the milks.
In a chilled bowl, whip the heavy cream with sugar and vanilla extract until soft peaks form. Spread or pipe the whipped cream over the soaked cake.
Sprinkle cinnamon over the whipped cream for that inviting, aromatic finish. Slice and serve chilled for the best experience.