Preheat your oven to 350°F (175°C) and grease a doughnut pan.
In a large bowl, whisk together the flour, 1/2 cup sugar, baking powder, salt, and cinnamon.
In another bowl, combine the milk, eggs, melted butter, and vanilla extract. Mix well.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Spoon the batter into the prepared doughnut pan, filling each cavity about 2/3 full.
Bake for 10-12 minutes or until the doughnuts are golden brown and a toothpick inserted into the center comes out clean.
Allow the doughnuts to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.
While the doughnuts cool, whip the heavy cream until stiff peaks form.
Once the doughnuts are cool, pipe or spread the whipped cream on top of each doughnut.
Sprinkle 1/4 cup of granulated sugar evenly over the whipped cream.
Using a kitchen torch, carefully caramelize the sugar until it forms a crispy, golden crust. Allow to cool slightly before serving.