Preheat the oven at 175ºC/350ºF conventional oven and prepare a 20x20 cm square baking pan with parchment paper.
Sift together the all-purpose flour, baking powder and salt and set it aside.
240 g all-purpose flour, 1 ¼ teaspoon baking powder, ¼ teaspoon salt
In a large bowl using an electric hand mixer or in a bowl of a stand mixer, add the butter, and granulated sugar and mix it on high speed for 3 minutes.
150 g granulated sugar, 85 g butter
Add the eggs one at a time into the mixture and mix it in until combined.
2 eggs
Continue by adding half the dry ingredients, on low speed, mixing until just combined.
Then add the sour cream, vegetable oil, vanilla extract and mix until just combined. Then add the other half of the dry ingredients and mix until combined.
25 g vegetable oil, 1 teaspoon vanilla extract, 150 g sour cream
Using a rubber spatula, give the batter a gentle fold to make sure all of the ingredients have combined.
Add the cake into the prepared pan and make the strawberries.