Preheat your oven to 350 degrees F. This initial step is crucial for ensuring a perfect bake; make sure your oven is fully heated before you introduce your batter.
Grease a 9x13-inch baking pan with cooking spray and set it aside. This will help the cake release easily once it’s baked, ensuring a beautiful finish.
In a large bowl, combine both sugars, pumpkin puree, vegetable oil, eggs, and vanilla extract. Using an electric mixer on medium-low speed, beat these ingredients together until just combined, which should take about 30 seconds. The mixture should look smooth and slightly frothy.
In a medium bowl, whisk together flour, baking powder, baking soda, salt, and the spices. Mixing these dry ingredients ensures that all the leavening agents and flavors are evenly distributed.
Gradually add the flour mixture to the pumpkin mixture, then beat on medium speed until fully combined. The batter should be thick yet pourable and well-mixed without any lumps.
Transfer the batter to the prepared pan, smoothing it out with a spatula to create an even layer. This step is essential for even baking and a nice, flat cake top.
Bake for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean or with just a few crumbs attached. Be careful not to overbake, as this could lead to a dry cake.
Once baked, place the cake on a cooling rack and let it cool for 15 minutes. This allows it to set before adding the tres leches mixture.
In the meantime, whisk together heavy whipping cream, evaporated milk, sweetened condensed milk, and ground cinnamon in a medium bowl until well combined. This delicious liquid will soak into the cake.
Using the end of a wooden spoon, poke holes all over the warm cake. This will help the milk mixture soak in deeply, infusing every bite with flavor.
Pour the milk mixture evenly over the cake, ensuring every inch is covered. Cover the cake with plastic wrap and refrigerate for at least 8 hours or overnight. This soaking process is what makes the cake so moist and flavorful.
Just before serving, prepare the maple whipped cream topping. In a large cold bowl, whip together heavy whipping cream, confectioners' sugar, maple syrup, maple extract, and cinnamon until stiff peaks form, which should take about 5 to 7 minutes. The whipped cream should be light and fluffy.
Spread the whipped cream evenly over the cake, creating a beautiful layer on top. Optionally, sprinkle ground cinnamon for a finishing touch.
Slice and serve your Tres Leches Pumpkin Cake. Enjoy the delighted reactions from those you share it with!