Combine cake mix, eggs, water, oil, sweetened condensed milk, and flour in a mixer to combine on medium for 2-3 minutes.

Fold in 1 pint blueberries.

Fill in cake liners (2/3 full) and bake at 325 degrees F. for 20 minutes or until toothpick inserted comes out clean.

Let cool while preparing frosting.

In an electric mixer fit with paddle attachment, cream butter until light and fluffy.

Add in powdered sugar 1 cup at a time, mixing well between each addition.

Add in vanilla extract and heavy cream.

Beat frosting at medium for 3 minutes.

Add in remaining blueberries to frosting and mix well.

Pipe cupcakes and enjoy!