SAN FRANCISCO — Two Bay Area-based brands have partnered to debut a gluten-free muffin mix formulated with upcycled ingredients.

Renewal Mill transforms the leftover pulp from plant milk production into “climate-friendly flours” and baking mixes. Its latest launch, a chai oat muffin mix, was developed in collaboration with specialty sweetener brand Just Date. The product is made with Renewal Mill’s upcycled oat milk flour and organic date sugar derived from dried and ground kentichi dates that previously were wasted.

Claire Schlemme, co-founder and chief executive officer of Renewal Mill, said the “deep caramel flavor” of the date sugar pairs well with the protein-rich oat milk flour.

“Using alternative sweeteners opens the door to a whole new set of customers who can engage with Renewal Mill baking mixes and upcycled ingredients for the first time,” Ms. Schlemme said.