After an overwhelming response for this hat on social media, I decided to write up the pattern. This hat is easy to make in any size and any weight of yarn, just use the appropriate hook.
If you wish to buy an inexpensive printable PDF for this pattern you can buy it from my Etsy shop here. Below is the free pattern. So here we go.

Materials

Yarn: worsted weight yarn, I used Caron cakes.
Hook: 4mm and 5mm
Tapestry needle
Scissors

Pom pom maker (optional)

Abbreviations:

ch : chain
sc: single crochet
ss: slip stitch
hdc: half double crochet
hdc2t: half double crochet 2 together
YO: yarn over

Special stitches:
First star stitch: to begin a new round of star stitches, chain 3 then
insert into 2nd ch from hook, yarn over and pull up a loop - 2 loops on hook
Insert into 3rd chain from hook, pull up a loop - 3 loops on hook
Insert into the 1st stitch of the round and pull up a loop - 4 loops on hook.
Insert into next 2 stitches and pull up a loop each - 6 loops on hook
YO and pull through all 6 loops.
Ch1 to form the eye of the star stitch.

Star Stitch: insert into the eye of the previous star stitch and pull up a loop - 2 loops on hook
Insert around the last post of the previous star stitch and pull up a loop - 3 loops on hook.
Insert into the same stitch as the last post of the previous star stitch and pull up a loop - 4 loops on hook
Insert into next 2 stitches and pull up a loop each - 6 loops on hook
YO and pull through all 6 loops.
Ch1 to form the eye of the star stitch.

Special sc2t: working in the star stitch round, insert hook into the eye of the previous star stitch and pull up a loop, insert hook into the slip stitch of the previous round and pull up a loop, YO pull through the 3 loops on hook.

hdc2t: YO and insert into stitch, YO and pull up a loop, 3 loops on hook. Insert into next stitch and pull up a loop, 4 loops on hook. YO and pull through 4 loops on hook.

Note: Measure the head you want to make the beanie for. With the smaller hook  create a ribbing of single crochets worked in the back loops only and make sure you have odd number of rows. Then work rest of the hat with the larger hook. A size chart can be found here.

Ribbing:
With smaller hook chain 8 for baby/toddler sizes , 9 for kids/teen size and chain 11 for adult size hat or more if you want the brim to be wider.

Row 1: sc in the 2nd chain from hook and all the way across, ch 1 and turn

Row 2:  sc BLO in the 1st st, that is the same as your ch1 and all the way across, ch1 and turn.

Now repeat Row2 until your piece measures half inch less than the head measurement. Making sure you have odd number of rows.

Join the 2 ends of the ribbing together with a ss to form a circle. Turn the ribbing inside out so that the slip stitch is on the inside.

Hat:
Ch 1 and begin working in rounds.
Round1: sc evenly across each row of the brim ss to 1st sc of the round. You must have odd number of stitches.

Round2: ch1 and work a hdc in the same stitch as the ch1 and all the way across, join with a ss into the 1st hdc of the round.

Round3: ch1 and work a sc into the 3rd loop of the 1st hdc from previous round. This is a little tricky so make sure you don't miss the first stitch. Work a sc in all the stitches in the round. The 3rd loop of a hdc is on the wrong side of the stitch so turn your work slightly inwards to see the 3rd loop. This stitch is also called a hdc camel stitch.

Round4: work the first star stitch and then the rest of the star stitches in the round. After you have worked your last star stitch, work the special special sc2t and join in the round. You should have half the number of star stitches as your beginning sc and a special sc2t.

Round5: ch1 and work 2 sc in each eye of the Star Stitch from the previous round, work 1 sc into the sc2t from the previous round. You should have the same number of stitches as round 1.

Repeat rounds 2-5 as many times as needed to reach 1 inch short of  the height of the hat.

Typically 1 more time for baby size, 2 for child and 3 times for young adult/ adult sizes.

Round6: ch1 hdc2t across the round, working a hdc in the last stitch and join with a ss.

Round7: Repeat Round4

Round8: Repeat Round5

Round9: Repeat Round 6

Fasten off leaving a long tail.
Thread the tapestry needle with the tail and work a running stitch in the last round, pull tight to close the hole on the top and weave in the end.

You can either stop here or attach a pom pom on top. 

Special note: to make a messy bun beanie stop at round 8 and work a round of sc around a hair tie.

Please leave your suggestions/ thoughts and experiences with this pattern in the comments below.