For the Cupcakes: Position rack in middle of oven. Preheat oven to 350°F/180°C. Line 32 mini-cupcake wells with mini fluted paper liners; set aside.

Whisk together the flour, salt and baking soda together in a small bowl to aerate and combine; set aside.

Cream butter with electric mixer in a large mixing bowl on high speed, until creamy. Add the sugar and continue beating until smooth and creamy, about 3 minutes, scraping down bowl as needed. Beat in vanilla and egg until incorporated.

Add the flour mixture and the sour cream and beat on medium speed until a few floury streaks remain. Add 1/3 cup coconut and beat until batter ingredients are combined.

Divide the batter in prepared cupcake tins and bake for about 12 to 17 minutes or until a toothpick inserted in the middle of a cupcake shows a few moist crumbs clinging. The cupcakes will dome, and will remain fairly pale. Cook cupcake tin on rack for 5 minutes, then remove cupcakes from pan and cool directly on rack until cooled.

For the Frosting: Whisk the milk and flour together in a small saucepan. Bring to a simmer over medium heat, whisking constantly. Once it simmers, continue whisking and cook for 1 to 2 minutes or until thickened, smooth and glossy. It should be thick enough for you to be able to see whisk marks. Remove from heat and set aside, whisking occasionally until cool. Meanwhile, in a medium bowl with an electric mixer on medium-high speed, beat butter until creamy, about 2 minutes. Add sugar and beat on high speed until light and fluffy, scraping down the bowl as needed. Beat in vanilla, then add cooled, cooked flour mixture and beat until smooth.

Frosting is ready to use. If the frosting is not silky smooth, it is because it is too cool. Either keep beating or remove about 1/2 cup (120 ml), zap in microwave for 5 seconds to soften, then add it back to the main batch and beat vigorously. Repeat as needed. Don’t be afraid to “work” this frosting. It can make the difference between the frosting being just okay and truly ultra silky.

For the Decoration: Frost each mini cupcake with about 1 tablespoon of frosting and top with sweetened long-shred coconut. Mini cupcakes dry out very easily due, in part, to their diminutive size. These are best eaten the day they are made. They can be held for 24 hours at room temperature in a single layer in an airtight container. Do not refrigerate and definitely serve at room temperature.