Preheat your oven to 350°F (175°C) and prepare a 9x5 inch loaf pan with non-stick cooking spray or butter.

Cream softened butter and granulated sugar in a large mixing bowl using a hand mixer until light and fluffy, about 2-3 minutes.

Add eggs and vanilla extract, mixing on low until combined, then add sour cream and whole milk, blending until smooth.

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

Gradually add dry ingredients to wet mixture, mixing gently until just combined, then fold in Christmas sprinkles.

Pour the batter into the prepared pan and bake for 60-70 minutes, until a toothpick comes out clean.

Let the loaf cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Prepare the glaze by whisking together powdered sugar, heavy cream, and vanilla extract until smooth.

Once the bread is completely cooled, drizzle the glaze on top and add extra Christmas sprinkles if desired.