Good question, Carrie Underwood. How is it possible that your baby boy Jacob is already 12 months old?

The proud mother posted on Tuesday (Jan. 21) -- Jacob's first birthday -- with pictures of him devouring a cake.

"Happy birthday, Jacob! How are you already 1 year old? You are smiley, crazy, smart, soooo fast and into everything! And, apparently, you love cake! I can’t wait to see your personality continue to shine! I have a good feeling you’re going to keep us all on our toes for years to come! I thank God for you each and every day. You are truly our miracle baby!!! Mommy loves you," Underwood shared with her son and her fans.

"Swipe to see how cute the cake was before Jake got ahold of it!"

Jacob Bryan Fisher was born on Jan. 21, 2019, and at the time, Underwood called him her little miracle.

"(He) entered the world in the wee hours of the morning on Monday…his mom, dad and big brother couldn’t be happier for God to trust them with taking care of this little miracle,” they wrote in the social media post with a trio of photos from the delivery room. In each picture, someone from the family is treasuring time with the baby boy: Underwood, her husband Mike Fisher, and their then 3-year-old Isaiah.

“Our hearts are full, our eyes are tired and our lives are forever changed,” they said. “Life is good.”