In a large skillet over medium heat, cook almonds, garlic, and bread, tossing frequently, until lightly browned, 5 to 8 minutes. Transfer to a plate to cool completely.
Place almond mixture in a food processor; process until finely ground. Add tomatoes, pimientos, vinegar, paprika, and cayenne; process until smooth. With motor running, gradually add oil; process until combined. Season with salt and pepper. To store, refrigerate up to 1 week, or freeze.
Spoon 2 tablespoons mixture into each section of an ice-cube tray. Freeze at least 1 hour; transfer cubes to a resealable plastic bag, and freeze up to 3 months. You can also freeze sauce in airtight containers, leaving 1/2 inch of space, up to 3 months. Cubes thaw in 15 minutes at room temperature; thaw larger quantities in the microwave or in the refrigerator overnight.