Heat the oven to 350°F and line an 8 inch by 4 inch loaf pan with parchment paper. Leave enough parchment above the pan edges to help lift out the cooled loaf.

Microwave the riced cauliflower for 3 to 4 minutes until tender, then let it cool before wrapping small portions in a tea towel and squeezing firmly. Continue in batches until the cauliflower feels dry and compressed rather than wet or steamy.

Beat the egg whites at high speed in a mixing bowl until stiff peaks form, then set them aside. When the beater is lifted, the peaks should stand upright and hold their shape.

Whisk the egg yolks, oil, almond flour, baking powder, and salt in a large bowl until they form a smooth, thick paste, then stir in the dried cauliflower. The cauliflower should be evenly distributed with no dry pockets of almond flour.

Fold about ¼ of the whipped whites into the cauliflower mixture with a spatula, then continue adding the remaining whites in batches until incorporated. Stop folding when the batter looks pale, fluffy, and evenly combined, without streaks of egg white.

Transfer the batter to the lined pan and bake for about 45 to 50 minutes, then cool the loaf before slicing. The top should look golden and set, and the cooled loaf should cut into clean slices without collapsing.