Step 1Heat the oven to 350 degrees. Coat a 12-cup standard muffin tin with nonstick baking spray.
Step 2Whisk the flour, baking soda, baking powder and salt in a large bowl. Whisk the macadamia milk, coconut oil, both sugars, the vinegar and vanilla in a medium bowl until the sugars dissolve. Pour the wet ingredients into the dry ingredients and stir gently with the whisk until no dry bits remain and the batter is almost smooth.
Step 3Add the strawberry jam to the batter and fold gently until evenly swirled. Divide the batter evenly among the prepared muffin cups and press the strawberries evenly into the tops.
Step 4Bake, rotating the pan once, until golden brown and a toothpick inserted in the center of a muffin comes out clean, about 30 minutes.
Step 5Cool the muffins in the pan on a wire rack for 15 minutes, then unmold and cool completely on the rack.