Start by preheating an oven to 180c (350f) and prepare a 10-inch round baking pan with parchment paper.
Make the crumble topping: In a medium mixing bowl, add the flour, kosher salt, brown sugar, and cinnamon. Mix with a spoon until the mixture is well combined.
Add the melted butter and mix until well combined. Place in the fridge while you make the cake.
Into a large mixing bowl, add the cooled melted butter, eggs, granulated sugar, vanilla extract, lemon zest, buttermilk, kosher salt, and Greek yogurt, and mix with a whisk until well combined.
Add the flour, baking powder, and baking soda, and mix until just combined and there are no lumps of flour visible.
Pour the cake batter into the parchment paper-lined baking pan and smooth it out with an offset spatula. Pit the cherries and cut them in half. Top the cake batter with an even layer of cherries.
Top the cake with the streusel topping and press the streusel topping onto the cake batter so it sticks and does not fall off while baking.
Bake in a 180c (350f) preheated oven for about 60-70 minutes or until a toothpick inserted into the cake comes out clean, usually with a few crumbs.
Notes
Push the streusel topping onto the cake lightly so it would stick to the top of the cake while baking and not fall off.
Choose ripe cherries. Select plump, juicy cherries for the best flavor. Fresh cherries are ideal, but frozen ones can work well too if fresh aren't available.
Use room temperature ingredients. It is important that you use room-temperature ingredients like eggs and milk. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly. you don’t want to place cold batter into the oven.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have moist cake and not dense and dry cake.
Pit the cherries carefully. Use a cherry pitter to remove the pits without damaging the fruit. If you don't have a pitter, a small knife or paperclip can work in a pinch.
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Test for doneness carefully. Insert a toothpick into the center of the cake to check if it's done. Be mindful of cherry juice that might make the toothpick appear wet even when the cake is fully baked.
Be patient! I know it's extremely tempting to eat this cake as it is pulled out of the oven, but let this cake cool for at least 1 hour so it will be firmer and won't crumble up.