Preheat the oven to 350°F (175°C). Generously grease a 10-inch Bundt pan with butter or non-stick spray and lightly dust with flour, tapping out the excess.

In a medium bowl, whisk together the flour, baking powder, baking soda, fine sea salt, and ground cinnamon until evenly combined.

In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter and cream cheese on medium speed until light and fluffy, about 2–3 minutes.

Gradually add the granulated sugar, continuing to beat until the mixture turns pale and increases in volume.

Add the eggs one at a time, beating well after each addition, then mix in the vanilla extract.

Reduce the mixer speed to low and slowly add the dry flour mixture, scraping the sides as needed, mixing just until incorporated. Do not over-mix.

Stir together the granulated sugar, ground cinnamon, and melted butter to form a thick paste. Fold the cinnamon-sugar mixture into the batter, reserving a small spoonful for the final glaze.

Pour the batter into the prepared Bundt pan, smooth the top, and tap the pan gently on the counter to release air bubbles.

Bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean and the top is a deep golden brown.

Allow the cake to cool in the pan for 10 minutes, then invert onto a wire rack. While the cake is still warm, brush the reserved cinnamon-sugar mixture over the top, letting it melt into a glossy glaze that crackles as it sets.