In a large bowl, cream together the butter and sugar. Add eggs and vanilla and continue to mix well.
In a separate bowl, sift together the flour, baking powder and poppy seeds. Gradually add the dry ingredients to the butter and beat well.
Divide the dough into 4 parts and roll each part into a long log-like shape, about 1-inch wide in diameter. Wrap each long individually in plastic wrap and gently place in the freezer for at least 1 hour or until firm.
Preheat oven to 350℉.
Remove 1 log at a time from the freezer and roll it a few times back and forth on the counter to reform its log shape. Remove the plastic wrap. Cut thin slices into the log and lay the slices out on a parchment-lined cookie sheet. Repeat with remaining logs.
Bake for 15 minutes and enjoy!
Notes
Some people like these just lightly toasted while others love the slightly burnt cookies. You can slice them a bit thinner or thicker depending on your personal preference!