Preheat your oven to 350-F.
Butter the cake pan with some butter, then sprinkle the bottom of the pan with 1/4 cup of the sugar. You can tilt the pan around to get an even layer of sugar.
Arrange the strawberries in the bottom of the pan, with the uncut side facing up. The strawberries should be close and even overlapping if you can manage it.
Whisk the flour, baking powder, baking soda, and salt in a bowl.
Beat the remaining butter and remaining sugar in a bowl with your stand mixer and paddle attachment or with a hand mixer. Beat until fluffy and lighter in color.
Beat in the egg, egg yolk, sour cream, and vanilla extract.
Add the flour mixture in thirds, mixing well in between and scraping down the sides of the bowl as needed.
Pour the cake batter gently over the top of the strawberries, being careful not to jiggle them around too much.
Bake the cake for about 50 minutes or until an inserted toothpick comes out almost clean (a few clinging crumbs are OK).
Cool the cake in the pan until it is very nearly room temperature, then place an inverted plate over the top of the cake pan and carefully turn the cake over and out onto the plate.
Cut, serve, and enjoy!