Yes, I've blogged about these in the past. They are the most popular cookie I make. So I will just copy a post I made last year about them and you get the repeat. They are that good!
Log Jams. Easy peasy!
Begin with 12 ounces unsalted butter, softened
1 cup of granulated sugar
2 egg yolks
2 teaspoons of vanilla
3 cups of flour
As usual, cream together the butter and sugar. Add in the egg yolks and vanilla. Mix in flour a cup at a time. Roll dough into 3 logs about an inch in diameter. Press a well into the center of the logs. Fill with your favorite jam, I always use seedless raspberry jam. Be careful! These cookies spread out, only put two logs on a cookie sheet at a time. Bake for 15 minutes at 325 degrees. Allow to cool completely. Drizzle a lemon glaze over the top when they're cool. Slice diagonally into 1 inch slices. Store in an airtight container for up to a week.
The glaze is easy to make. 1 cup of powdered sugar, 1 tablespoon of lemon juice, mix together add milk to get to a drizzle consistency. Drizzle over logs.