Measure protein powder, milk, Greek yogurt, oats, almond butter, ground flaxseed, and optional flavorings. If banana is not frozen, slice and place in freezer for 20–30 minutes to chill (or use pre-frozen). Toast oats or chop nuts for garnish if using.

Blend the Shake

Add liquids and soft ingredients

Pour 1.5 cups of milk into the blender. Add 0.5 cup Greek yogurt and 0.5 of a sliced frozen banana. Add 0.5 tsp vanilla extract if using.

Add dry and thickening ingredients

Add 2 scoops vanilla protein powder, 0.25 cup rolled oats, 1 tablespoon ground flaxseed, and 1 tablespoon almond butter to the blender. Add optional 1 tsp honey or maple syrup and 1/8 tsp ground cinnamon if desired.

Add ice and blend

Add 4 ice cubes to the blender. Secure lid and blend on high for 45–60 seconds, or until the mixture is smooth and creamy with no large ice or oat pieces. If too thick, add up to 2–4 tablespoons (30–60 ml) additional milk and blend briefly. If too thin, add 1–2 more tablespoons of oats or one more ice cube and pulse.

Serve

Pour the shake into a 16–20 oz glass. Garnish with a banana slice and a sprinkle of toasted oats or chopped nuts if desired. Serve immediately.

Store any leftover shake covered in the refrigerator for up to 24 hours; shake or stir before drinking (texture may separate).