Lemon cupcakes with lemon cream icing

I know making cupcakes from scratch is old news, but when I had .79 Duncan Heinz cake mix at my finger tips I just never bothered to try. Things are different here and I don't know if I can go back to the boxed mix after I've seen the light. Jason requested lemon cupcakes for his birthday (we've been married for 14 years and I am just now learning that lemon is his favorite. I'm not sure exactly what that says...). They got two thumbs up and just may be on the regular birthday rotation from now on.

3 cups self-rising flour
1/2 teaspoon salt
1 cup butter, at room temperature
2 cups white sugar
4 eggs, at room temperature
1 teaspoon vanilla extract
2 tablespoons lemon zest
1 cup whole milk, divided
2 1/2 tablespoons fresh lemon juice, divided
Lemon Cream Icing:
2 cups chilled heavy cream
3/4 cup confectioners' sugar
1 1/2 tablespoons fresh lemon juice
*yield 30 cupcakes
Preheat oven to 375. Sift flour and salt together in a bowl. In another bowl, beat the butter and sugar with an electric mixer until light and fluffy. Beat in the eggs one at a time. Mix in the vanilla and lemon zest. Gently beat the flour mixture into the butter mixture, one third at a time, alternating with half the milk and half the lemon juice after each of the first 2 additions of flour. Beat until just combined; do not over mix. Fill cupcake liners 3/4 full, and bake for about 17 minutes. To make the icing, beat the cream with an electric mixer set on Low until it begins to thicken. Add the confectioners' sugar and lemon juice, a little at a time. Increase the mixer speed to High, and beat until the icing forms soft peaks, about 5 minutes. Spread on the cooled cupcakes. Refrigerate leftovers.