Whisk together flour, baking powder, baking soda, cinnamon, and salt. In another bowl, cream butter with sugar. Beat in eggs one at a time. Gradually stir in buttermilk and vanilla. The mixture may appear curdled, but that is OK. Pour the wet ingredients into the dry ingredients and stir until just combined, being careful not to over-mix. Gently stir in the diced rhubarb.
Place a heaping tablespoon of batter into each muffin cup. Layer with about 1 tablespoon of cheesecake filling, and then cover that completely with more muffin batter, filling the cups almost full. Sprinkle each muffin evenly with crumb topping and press the crumbs into the batter so that they adhere.
Bake the muffins for 5 minutes at 425F degrees. Lower temperature to 350F and continue baking for an additional 15 minutes, or until a toothpick inserted in the center comes out clean. Cool the muffins for 5 minutes in the tins before putting them onto a wire rack to cool completely.