Hilary Duff carried Luca, who rested his head on his mom's shoulder, in her arms as she ran errands around LA yesterday. She's been focusing much of her attention on her little man recently, especially since his exciting milestone. Luca turned 1 last week, and he celebrated by attending a Babies First Class in LA with Hilary. The proud mom was also sure to have a standout cake, which seemed to be a highlight of the festivities. Hilary shared a picture of the robot confection on her Twitter account, saying, "Thank you Duff's cake mix for the coolest 1 year old's robot birthday cake ever! It was a big hit!"