In a large bowl, using an electric mixer, cream together the softened butter and granulated sugar until light and fluffy.

Add in the eggs, one at a time, and pour in the vanilla extract. Mix on medium speed until completely combined.

In a separate medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon.

In a measuring cup, whisk together the sour cream and milk until smooth.

Gently add half of the dry ingredients to the butter mixture, followed by the entire milk mixture, and then the remaining dry ingredients. Mix until just combined.

Turn the dough onto a well-floured surface. Dust with a light coating of flour and knead the dough 2-3 times until it becomes a cohesive ball. Roll the dough to about ⅓-inch thickness.

Use a donut cutter or two circular cutters of different sizes to cut out donut shapes, ensuring you dip them in flour first to prevent sticking. Re-roll any scraps.

In a large heavy-bottomed pan or Dutch oven, heat the canola oil until it reaches 375°F.

Carefully place 2 donuts into the hot oil using a slotted spoon, cooking them for about 2 minutes on one side, then flipping them to cook for an additional minute. Remove from oil and let drain on a cooling rack.

In a small saucepan over low heat, combine the chocolate chips, heavy whipping cream, light corn syrup, and vanilla. Stir until completely melted and smooth.

Allow it to thicken slightly before using for dipping. Dip one side of the donuts into the chocolate glaze and sprinkle with your favorite toppings.