Preheat your oven to 350°F (180°C) conventional (see note 2 if using a convection oven). Lightly grease an 8.5 x 4.5-inch loaf pan, then line it with parchment paper, leaving some overhang on the sides to make it easier to lift the cake out later.
In a medium bowl, sift together the flour, cornstarch, baking powder, and salt. Whisk everything together until evenly combined, then set aside.
In a large bowl, add the unsalted butter and beat using a hand or stand mixer on medium speed for about 1 minute, until smooth and creamy. Add the sugar and oil, then continue beating for another 2 minutes, until the mixture is light and creamy.
Next, add the eggs one at a time, mixing on low speed after each addition until just incorporated before adding the next egg.
Add the milk and vanilla, then mix on low speed until everything is well combined.
Add the sifted dry ingredients to the wet mixture and mix on low speed until just combined. Be careful not to overmix the batter (see note 3). As soon as you no longer see any large streaks of flour, stop mixing. You can use a spatula to scrape the bottom of the bowl to ensure everything is evenly mixed, but again, do not overmix! :)
Pour the batter into your prepared loaf pan and spread it into an even layer. Gently tap the pan on the counter once to help settle the batter and get rid of any large air bubbles.
Bake for 60 minutes, or until a skewer or thin knife inserted into the centre comes out clean or with a few moist crumbs attached. If you notice the top overbrowning and beginning to burn, lightly tent the top of the pound cake with foil.
Allow the pound cake to cool in the pan for about 20 minutes before running a thin knife along the edges of the pan not lined with parchment, then use the overhanging paper to lift the loaf out of the pan and place it on a wire rack to cool completely.
Once cooled, slice and serve as is or with homemade whipped cream and fresh fruit like strawberries on the side!