In a medium bowl, combine all-purpose flour, brown sugar, and ground cinnamon. Cut in cold butter until crumbly and refrigerate.

Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking pan and dust with flour.

In a medium bowl, whisk together all-purpose flour, baking powder, baking soda, and salt.

In a large mixing bowl, cream together granulated sugar and softened unsalted butter until light and fluffy.

Add eggs one at a time and mix in vanilla extract until smooth.

Gradually add the dry ingredients alternately with buttermilk, mixing until just combined.

Fold in the halved, pitted cherries gently.

Pour the batter into the prepared baking pan and spread evenly.

Sprinkle the chilled streusel topping over the batter.

Bake for 35-40 minutes or until a skewer comes out clean.

Cool in the pan for 10-15 minutes before transferring to wire rack.

For the optional glaze, whisk powdered sugar with milk or cherry juice and drizzle over the cooled cake.