Make the pasta: In a mixing bowl, add flour and water. Slowly add the flour from the sides to the center, stirring to incorporate. Mix until a dough forms, and then knead on a floured surface for 8 to 10 minutes. Cover the dough with a kitchen towel and allow to rest for 20 minutes.
Flatten the dough into a round pancake and cut into strips. Using one strip at a time, roll into a long rope, then cut into 1/3-inch pieces. Press and roll each piece of dough towards yourself and create a curl. Pick up dough piece and invert it over your thumb. Transfer to a parchment-lined tray that is dusted with flour. Repeat with remaining dough and set aside.
Put a large pot of water on to boil.
Cook the broccoli rabe: Add anchovy oil to a skillet over medium-low heat, add anchovies and gently stir until they begin to melt. Stir in garlic and half the packet of red pepper flakes and continue cooking for a few minutes.
Using a vegetable peeler, shave off a little bit of each stalk of the broccoli rabe and then chop.
Add broccoli rabe to the pan and saute a few minutes. Add a couple tablespoons of water to the pan and cook for 20 seconds. Add the pasta to the boiling water and cook for 2 to 3 minutes, then add to the pan with the broccoli rabe. Finish with butter packets and remaining red pepper flakes.