This Chia seed muffin mixes can be used with the lemon juice or just plain as a simple vanilla sponge. We also love to swap the lemon for orange juice and zest for a yummy orange muffin to scoff for afternoon tea. For a jammy surprise, we love to sneak a blob of low GI jam in the middle of the lemon-free mix before baking! This Chia seed muffin mixes can be used with the lemon juice or just plain as a simple vanilla sponge. We also love to swap the lemon for orange juice and zest for a yummy orange muffin to scoff for afternoon tea. For a jammy surprise, we love to sneak a blob of low GI jam in the middle of the lemon-free mix before baking!