Line an 8x4-inch baking pan with waxed or parchment paper. Set aside.
In a bowl, combine peanut butter, water, maple syrup and vanilla extract until smooth. Add oat flour, rolled oats, soy protein powder and flaxseed meal and mix until combined. This is a dry dough and may be a bit crumbly.
Press the oat mixture evenly into the bottom of the prepared pan, smooth top and set aside.
In a small bowl or saucepan, gently heat chocolate chips until melted, taking care not to burn. Pour melted chocolate over oat layer and smooth with a spatula to cover evenly. Sprinkle toasted sliced almonds over the chocolate layer and press gently to secure.
Transfer baking dish to the refrigerator or freezer to set the chocolate, about 10 minutes.
To portion, run a knife around the inside edge of the dish and use the waxed or parchment paper to lift the uncut bars out of the pan. Using a sharp knife, cut into six bars.