1. Preheat your oven to 175°C (350°F). Line 1-2 baking trays with parchment paper and set them aside.

2. In a large mixing bowl, using a handheld electric beater, beat together the softened unsalted butter, vegetable oil, and 100g granulated white sugar until the mixture is light, fluffy, and pale in color.

3. Beat in the room temperature egg and 2 teaspoons of vanilla extract until they are fully combined.

4. Using a spatula, gently fold in the plain flour, salt, and baking powder. Mix until just combined. Be careful not to overmix.

5. Scoop out 11 equal-sized cookie balls (approximately 2 tablespoons each) and place them on the prepared baking trays, ensuring they are evenly spaced.

6. Gently flatten each cookie ball slightly with your hands. This helps them spread evenly and achieve the classic shortcake cookie base shape.

7. Bake for 9-10 minutes, or until the edges are lightly golden. Allow the cookies to cool completely on the baking sheet before handling.

8. While the cookies cool, prepare your whipped cream. In a large, very cold mixing bowl, place the heavy cream, 2 tablespoons of granulated white sugar, and 1 teaspoon of vanilla extract. Using a handheld beater, beat them together on medium-high speed until medium peaks form.

9. Once the cookies are completely cool, scoop even amounts of the freshly whipped cream onto the top of each cookie. Smooth the cream over slightly, covering the top surface. Arrange the sliced fresh strawberries on top of the cream-covered cookies.

10. Serve immediately and enjoy your homemade Strawberry Shortcake Cookies!