Preheat your oven to 350°F. Grease the cake pan, including the sides.
Put the cake pan on your stovetop and melt the butter in it. Stir in the brown sugar, spread evenly over the bottom of the pan, then remove the pan from the stove.
Arrange the cherries flat-side down in the sugar mixture.
In a large bowl, sift flour, baking powder, and salt, then whisk to combine.
In a separate bowl, beat sugar and butter until light and airy.
Mix in the egg yolks one at a time. Mix in the vanilla.
Beat in the milk
Continue to mix until well-combined.
Gradually add in the flour until just combined.
Beat the egg whites and the cream of tartar together until stiff peaks form.
Fold into the cake batter until just combined.
Pour the batter into the cake pan.
Level out the bottom with a spatula. Bake for 55 minutes to 1 hour.
Remove the cake from the oven and let it cool for at least 10 minutes before running a knife around the edge of the cake to loosen it.
Place a serving platter over the cake pan, then flip the cake onto the platter. Allow the cake to cool another 5 minutes, then serve.
Notes
Use a 9 to 10-inch cake pan with sides that are at least 2-inches tall.
