For vanilla cookies, cream together butter and sugar until light and fluffy. Add vanilla and mix to incorporate. Slowly add flour and salt and mix until combined. Chill dough for at least an hour.
To make the peanut butter cream, mix peanut butter, butter and brown sugar until smooth.
For the chocolate glaze, heat chocolate chips and milk in microwave for 10-15 seconds, remove and stir until chocolate chips are melted (you may need to heat it for another 10 seconds). Although the chips may not look melted, they will usually melt quickly when stirred, from the residual heat. When smooth, add powdered sugar and stir until smooth again. Spoon into a piping bag.
When ready to bake cookies, heat oven to 350°F
Roll dough into 1 inch balls, then toss in granulated sugar. Using a glass with a flat bottom that is about 1 and a half inches in diameter, press the dough ball to flatten. Dip glass bottom into sugar between cookies to keep it from sticking.
Bake for 12-15 minutes until edges are golden. After removing from oven, allow to cool on baking sheets. Allow cookies to cool completely.
When cookies are cool, spread a thin layer of peanut butter cream onto each cookie.
Using the piping bag, drizzle chocolate glaze over cookies.
Allow to sit for several hours before storing so that the chocolate glaze can firm up.
*When pressing cookies, try not to press so hard that the edges crack. **It is important to cool cookies completely before frosting with peanut butter cream, or else the peanut butter cream will melt. ***Chocolate glaze will be wet when first applied, but it will firm up in a few hours. ****For the chocolate glaze, I'm sure you could also make it in a double broiler, but I always use the microwave. Just be sure not to let it heat in the microwave too long, to avoid burning the chocolate. It takes very little time to melt, usually 10-15 seconds.