The Tales of the Walking Dead star shared a series of photos of the baby boy wearing a knitted crown with the number one on it and enjoying chocolate cake.
In one photograph, Malcolm sits in his comedian father Mulaney’s lap as he smiles at the camera, with Munn holding the elephant-shaped cake and laughing beside them.
She wrote in the caption: “Just got back from celebrating ONE YEAR of the most joyful baby being in this world and in our lives. My son, my joy. Happiest Birthday, Malcolm Hiá»p! I love you so so so much.”
Munn also shared a second video showing Mulaney holding Malcolm up and encouraging him to put his hands in the cake. However, after the baby hesitated, Munn’s mother gets up and takes a small piece of icing off with her finger and feeds it to Malcolm, smearing his face.
“Mum!” Munn, who is half-Vietnamese and half-white, exclaims in the video as others in the party laugh. She captioned the video: “When your Asian mom gets impatient.”
“For what it’s worth, he did start eating the cake after that,” the actor added.
Known for the candid and honest posts about first-time motherhood, Munn frequently shares her struggles with postpartum life after giving birth to Malcolm in November 2021.
In April, she revealed that her hair was “falling out in chunks” when she joked that she would give it away once it’s in “better condition”.
Hair loss is normal within the first few months of having a baby and is known as “excessive hair shedding”, which is temporary.
According to the American Academy of Dermatology Association, most mothers “see their hair return to its normal fullness by their child’s first birthday”.
She also spoke of how she “only has love” for her postpartum body six months after giving birth, adding: “My body hasn’t snapped back, but it made this little guy so I only have love for it.”